TAKU SAKAI
| Emeritus Professor etc. | Emeritus Professor |
Researcher Information
Field Of Study
Career
Educational Background
Member History
- 2005 - Nov. 2006
第46回講演大会実行委員長, 銅及び銅合金技術研究会, Society - 2005
評議員, 軽金属学会, Society - 2000 - 2004
高温材料設計研究会世話人, 日本金属学会, Society - 2001 - 2003
理事, 日本鉄鋼協会, Society - 2001 - 2003
材料の組織と特性部会部会長, 日本鉄鋼協会, Society - 2002 - 2002
講演大会実行委員会, 銅及び銅合金技術研究会, Society - 2001
評議員, 日本金属学会, Society - 2001
関東支部理事, 日本金属学会, Society - 1997 - 2000
評議員, 軽金属学会, Society - 1997 - 1999
再結晶'99国際会議(JIMIS-10)議長, 日本金属学会, Society - 1994 - 1999
再結晶・集合組織研究会主査, 日本鉄鋼協会, Society - 1991 - 1998
評議員, 日本金属学会, Society - 1997 - 1997
講演大会実行委員長, 軽金属学会, Society - 1997
評議員, 日本鉄鋼協会, Society - 1992 - 1992
評議員, 日本塑性加工学会, Society
Research Activity Information
Award
Paper
- Continuous static recrystallization in ultrafine-grained copper processed by multi-directional forging
A. Takayama; X. Yang; H. Miura; T. Sakai
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ELSEVIER SCIENCE SA, 478, 1-2, 221-228, Apr. 2008, Peer-reviwed, Annealing processes in copper, processed by multi-directional forging to strains of epsilon = 0.4-6.0 at 300 K, were studied at 503-573 K. Strain-induced ultrafine-grained copper shows mainly grain coarsening behaviour, which is categorized in three stages, i.e. (1) an incubation period, (2) a rapid and limited grain growth and finally (3) a classical (normal) grain growth. That is, in situ or continuous static recrystallization (cSRX) takes place in stages 1 and 2. The annealing characteristics and the mechanisms of cSRX are discussed with reference to those of conventional discontinuous SRX (dSRX). (c) 2007 Elsevier B.V. All rights reserved.
Scientific journal, English - Mechanical Properties of Magnesium Alloy AZ31 after Sever Plastic Deformation
J. Xing; X. Yang; H. Miura; T. Sakai
Mater. Trans, 49, 69-75, 2008, Peer-reviwed
Scientific journal, English - Grain refinement in aluminum alloy 2219 during ECAP at 250 oC,
I. Mazurina; T. Sakai; H. Miura; O. Sitdikov; R. Kaibyshev
Mater. Sci. Eng. A, 473, 287-305, 2008, Peer-reviwed
Scientific journal, English - Microstructural Behavior of Al-Mg-Sc Alloy Processed by ECAP at Elevated Temperatures
O.Sitdikov; T.Sakai; E.Avtokratova; R.kaibyshev; K.Tsuzaki; Y.Watanabe
Acta Mater, 56, 821-834, 2008, Peer-reviwed
Scientific journal, English - Grain Refinement in a Commercial Al-Mg-Sc Alloy under Hot ECAP Conditions
O. Sitdikov; T. Sakai; E. Avtokratova; R. Kaibyshev; Y. Kimra; K. Tsuzaki
Mater. Sci. Engin., A, 444, 18-30., 2007, Peer-reviwed
Scientific journal, English - Effect of Initial Grain Size and Strain Path on Grain Refinement in Magnesium Alloy AZ31
X. Yang; H. Miura; T. Sakai
Materials Science Forum, 539-543, 1632-1637, 2007, Peer-reviwed
Scientific journal, English - Effect of Coherent and Incoherent Precipitates on High-Temperature Deformation of Copper
H. Miura; T. Sakai
Materials Science Forum, 539-543, 2149-2154, 2007, Peer-reviwed
Scientific journal, English - Low Temperature Superplasticity of Ultra-Fine Grained Magnesium Alloy AZ31
J. Xing; X. Yang; H. Miura; T. Sakai
Advanced Materials Research, 15-17, 467-472, 2007, Peer-reviwed
Scientific journal, English - Microstructural Evolution and Recrystallization Behavior in Copper Multi-Directionally Forged at 77K
Y. Nakao; H. Miura; T. Sakai
Advanced Materials Research, 15-17, 649-654, 2007, Peer-reviwed
Scientific journal, English - Stimulated Grain Refinement of Ni-Fe Alloy by Coarse Precipitates during Hot Multi-Directional Forging
H. Miura; T. Sakai; T. Ueno; N. Fujita; Y. Yoshinaga
Materials Science Forum, 550, 271-276., 2007, Peer-reviwed
Scientific journal, English - Annealing of Deformed Materials Developed by Continuous/ Discontinuous Dynamic Recrystallization
T. Sakai; H. Miura
Materials Science Forum, 550, 327-332, 2007, Peer-reviwed
Scientific journal, English - Nucleation of dynamic recrystallization at Grain Boundaries in Copper Bicrystals
H. Miura; T. Sakai; J. J. Jonas
Materials Science Forum, 558-559, 457-463, 2007, Peer-reviwed
Scientific journal, English - Effect of Deformation Temperature on Microstructure Evolution in 2219 Aluminum Alloy during ECAP
I. Mazurina; O. Sitdikov; R. O. Kaibyshev; H. Miura; T. Sakai
Materials Science Forum, 558-559, 545-550, 2007, Peer-reviwed
Scientific journal, English - Microstructural Evolution in a Commercial Al-Mg-Sc Alloy during ECAP at 300C
O. Sitdikov; T. Sakai; E. Avtokratova; R. Kaibyshev; T. Tsuzaki; Y. Watanabe
Materials Science Forum, 558-559, 569-574, 2007, Peer-reviwed
Scientific journal, English - Recrystallization Behavior of Ultra Fine-Grained Structure Induced by Mechanical Twinning in Cu-Zn Alloy
Y. Nakao; H. Miura; T. Sakai
Materials Science Forum, 558-559, 1329-1334, 2007, Peer-reviwed
Scientific journal, English - Cu-Zn合金の最終低温焼鈍工程における微視組織と機械的性質の変化
三浦博己; 稲生剛; 酒井拓; 山口洋; 山崎周一
銅と銅合金, 日本伸銅協会, 46, 1, 41-45, 2007, Peer-reviwed
Scientific journal, Japanese - 高強度微細粒黄銅の加工熱処理中の微視組織発達
三浦博己; 鮎川英幸; 酒井拓; 山口洋; 山崎周一
銅と銅合金, 日本伸銅協会, 46, 1, 46-52, 2007, Peer-reviwed
Scientific journal, Japanese - Cu-Be25合金の多軸鍛造処理後の時効硬化特性
村松尚国; 千葉広樹; 玉昌峰; 三浦博己; 酒井拓
銅と銅合金, 日本伸銅協会, 46, 1, 157-161, 2007, Peer-reviwed
Scientific journal, Japanese - Ultrafine grain development in copper during multidirectional forging at 195K
C. Kobayashi; T. Sakai; A. Belyakov; H. Miura
PHILOSOPHICAL MAGAZINE LETTERS, TAYLOR & FRANCIS LTD, 87, 10, 751-766, 2007, Peer-reviwed, Strain-induced evolution of ultrafine grains in pure copper was studied in multidirectional forging (MDF) at 195 K. The stress-strain behaviour was characterized by rapid strain hardening during early processing and the rate of strain hardening gradually decreased with straining, leading to an apparent steady-state flow at large cumulative strains of more than 5. The structural changes were associated with the development of high-density microshear bands crossed by MDF. The new fine grains 0.16 mu m in size, which was smaller than the subgrain size evolved during early deformation, were evolved primarily at microshear band intersections, and then the new fine grains filled out the whole sample as the number of microshear band intersections increased at large strains. This is essentially similar to continuous dynamic recrystallization. The size of new grains can be expressed by a power law function of flow stress with a grain size exponent of about -0.3. The kinetics of the strain-induced grain evolution is analyzed and the mechanisms are discussed.
Scientific journal, English - Nucleation of dynamic recrystallization and variant selection in copper bicrystals
H. Miura; T. Sakai; R. Mogawa; J. J. Jonas
PHILOSOPHICAL MAGAZINE, TAYLOR & FRANCIS LTD, 87, 27, 4197-4209, 2007, Peer-reviwed, Orientation-controlled copper bicrystals containing [001] symmetrical tilt boundaries aligned parallel to the loading axis were deformed in tension at 923 K and a strain rate of 4.2 x 10(-4) s(-1). The nucleation of dynamic recrystallization (DRX) was investigated along the grain boundary. For this purpose, both optical and orientation imaging microscopy methods were used. After grain-boundary migration (GBM) and bulging, nuclei appeared behind the most deeply indented grain boundary regions. The critical strain for nucleation was about one-quarter to one-half of the peak strain and depended on the misorientation angle. All the nuclei were twin-related (Sigma 3) to the matrices. Furthermore, all the primary twin traces were parallel to those of the inactive slip planes of the parent single crystals. Crystallographic analysis revealed the important role of the direction of GBM on twinning-plane variant selection. The characteristics of grain boundary nucleation depended sensitively on grain boundary character and on grain boundary mobility. The observed DRX nucleation mechanism is discussed in relation to the occurrence of GBM and twinning.
Scientific journal, English - Enhanced Grain Refinement Induced by Deformation Twining during Multi-Directional Forging of Cu and Cu-Zn Alloy
H. Miura; H. Nakao; T. Sakai
Trans Mater, 48, 2539-2541, 2007, Peer-reviwed
Scientific journal, English - Ｍicrostructural Ｅvolution at Ｇrain Ｂoundary in a Copper Ｂicrystal Ｄuring Ｍulity-Ｄirectional Ｆorging
H.Miura; Y.Yosida; T.Sakai
Ploblems of Material Science, N4, 52, 24-29., 2007, Peer-reviwed
Scientific journal, English - Variant selection of dynamically nucleated twins at triple junctions in a copper tricrystal
H Miura; T Sakai; JJ Jonas
SCRIPTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 55, 2, 167-170, Jul. 2006, Peer-reviwed, The preferential nucleation of grains at triple junctions (TJs) during high temperature deformation was investigated systematically using a copper tricrystal. Their relationships to the parent grain were also determined. All the new grains were twin-related to the matrix and were formed by means of grain boundary migration (GBM). Selection of the twinning plane depended sensitively on the direction of GBM and on the geometry of the grain boundaries composing the TJ. It did not seem to be affected by slip plane activity or by the Schmid factor of the parent grain. (c) 2006 Acta Materialia, Inc. Published by Elsevier Ltd. All rights reserved.
Scientific journal, English - 銅の極低温強ひずみ加工とその後の再結晶挙動
中尾佳史; 三浦博己; 酒井拓; 和田正彦
日本金属学会誌, 70, 434-439., May 2006
Scientific journal, Japanese - Effect of Second Phase Particles on Ultra-Fine Grain Evolution during Multi-Directional Forging of Austenitic Stainless Steel
H. Miura; H. Hamaji; T. Sakai; N. Fujita; Y. Yoshinaga
Materials Science Forum, 503-504, 293-298, 2006
Scientific journal, English - Strain Rate Effect on Fine Grain Development in 7475 Aluminum Alloy during Hot Multidirectional Forging
A. Goloborodko; O. Sitdikov; R. Kaibyshev; H. Miura; T. Sakai
Materials Science Forum, 503-504, 505-510, 2006
Scientific journal, English - Strain-Induced Grain Refinement of Magnesium Alloy AZ31during Hot Forging
X. Yang; J. Xing; H. Miura; T. Sakai
Materials Science Forum, 503-504, 521-526, 2006
Scientific journal, English - Microstructure Development during Equal Channel Angular Extrusion of an Al-3% Cu Alloy
I. Mazurina; R. O. Kaibyshev; T. Sakai
Materials Science Forum, 503-504, 829-834, 2006
Scientific journal, English - Fine-Grained Structure Formation in 7475 Aluminum Alloy during Hot Multidirectional Forging
A. Goloborodko; O. Sitdikov; H. Miura; T. Sakai
Materials Science Forum, 512, 79-84, 2006, Peer-reviwed
Scientific journal, English - 超微細粒銅合金の新しい創製法，銅と銅合金
三浦博己; 酒井拓
銅と銅合金, 日本伸銅協会, 45, 1, 95-99, 2006, Peer-reviwed
Scientific journal, Japanese - 大ひずみ加工AZ31マグネシウム合金の超塑性変形
刑 剋; 楊続躍; 三浦博己; 酒井拓
軽金属, 56, 716-720., 2006, Peer-reviwed
Scientific journal, Japanese - Isochronal annealing behavior of magnesium alloy AZ31 after hot deformation
XY Yang; H Miura; T Sakai
MATERIALS TRANSACTIONS, JAPAN INST METALS, 46, 12, 2981-2987, Dec. 2005, Annealing behaviors of hot-deformed magnesium alloy AZ31 were studied at temperatures of 373 to 673 K by optical and SEM/EBSD metallographic observation. The hot-deformed alloy had fine-grained structures developed by grain fragmentation due to continuous dynamic recrystallization (cDRX). Temperature dependence of the average grain size (D) is categorized into three temperature regions, i.e. (a) an incubation period for grain growth at < 450 K, (b) rapid grain coarsening at 473-523 K, and (c) normal grain growth at T > 550 K. The number of fine grains per unit area, however, is reduced remarkably even in region (a). These lead to grain coarsening taking place continuously in the whole temperature regions. In contrast, the deformation texture scarcely changes even after full annealing at high temperatures. It is concluded that the annealing processes operating in hot-deformed magnesium alloy with cDRXed grain structures can be mainly controlled by grain coarsening accompanied with no texture change, that is continuous static recrystallization (cSRX).
Scientific journal, English - Nucleation of dynamic recrystallization at triple junctions in polycrystalline copper
H Miura; T Sakai; S Andiarwanto; JJ Ionas
PHILOSOPHICAL MAGAZINE, TAYLOR & FRANCIS LTD, 85, 23, 2653-2669, Aug. 2005, The preferential nucleation of dynamic recrystallization (DRX) was investigated in copper polycrystals. DRX nucleation began to appear preferentially at triple junctions (TJs) at around 0.01 strain irrespective of the testing conditions, i.e. at only about 1/10 to 1/20 of the peak strain. The likelihood of DRX nucleation at TJs increased monotonically with strain. Furthermore, this probability also depended strongly on the strain rate, temperature and initial grain size. More than 80% of the grains nucleated at TJs were twins. The observed likelihood of DRX nucleation at TJs was closely related to the amount of grain-boundary sliding, fold formation at the TJs, the misorientation angle of the grain boundaries composing the TJ, and the angle between the tensile axis and the sliding grain boundary. The mechanisms determining the strain-rate dependence of DRX nucleation and twin formation are discussed in detail in relation to the above factors.
Scientific journal, English - Grain refinement in coarse-grained 7475 Al alloy during severe hot forging
O Sitdikov; T Sakai; A Goloborodko; H Miura; R Kaibyshev
PHILOSOPHICAL MAGAZINE, TAYLOR & FRANCIS LTD, 85, 11, 1159-1175, Apr. 2005, Grain refinement taking place in a coarse-grained 7475 Al alloy was studied in multidirectional compression at 490 degrees C and at a strain rate of 3 x 10(-4) s(-1). The integrated flow curve displays significant work softening just after yielding and an apparent steady-state plastic flow at high strains. The structural changes are characterized by the development of deformation or microshear bands in coarse-grain interiors, followed by homogeneous evolution of new grains at high strains. The new grains are considered to be developed by a kind of continuous reaction through grain fragmentation that is similar to continuous dynamic recrystallization ( cDRX). The mechanism of. ne grain production and the factors controlling grain refinement during hot multidirectional deformation are discussed in detail.
Scientific journal, English - Ultra-Fine Grain Development in Magnesium Alloy AZ31 during Severe Large Forging under Decreasing Temperature Conditions
J. Xing; Y. Soda; X. Yang; H. Miura; T. Sakai
Mater. Trans, 46, 1646-1650, 2005
Scientific journal, English - Effect of Strain Rate on the Formation of Fine-Grained Microstructure in a Cast Aluminum Alloy 7475 upon High-Temperature Upsetting
O. Sitdikov; A. N. Goloborodko; R. O. Kaibyshev; H. Miura; T. Sakai
The Physics of Metals and Metallography, 45, 106-117, 2005
Research society, English - Effect of Initial Grain Size on Deformation Behavior and Dynamic Recrystallization of Magnesium Alloy AZ31
X. Yang; M. Sanada; H. Miura; T. Sakai
Materials Science Forum, 488-489, 223-226, 2005
Scientific journal, English - Orientation Dependence of Ductility of Mg Single Crystals at Elevated Temperature
H. Miura; T. Sakai; H. Nogawa; Y. Watanabe; S. Miura
Materials Science Forum, 488-489, 597-600, 2005
Scientific journal, English - Grain Refinement in Magnesium Alloy AZ31 during Multidirectional Forging under Decreasing Temperature Condition
J. Xing; X. Yang; H. Miura; T. Sakai
Materials Science Forum, 488-489, 193-196, 2005
Scientific journal, English - 析出強化Cu-Fe-Cr合金の強ひずみ加工による微視組織の発達，銅と銅合金
三浦博己; 酒井拓
44, 68-72., 2005
Scientific journal, Japanese - Dynamic twin nucleation at triple junctions in Fe-32%Ni stainless steel
H Miura; S Andiarwanto; T Sakai; JJ Jonas
ICOTOM 14: TEXTURES OF MATERIALS, PTS 1AND 2, TRANS TECH PUBLICATIONS LTD, 495-497, 1159-1164, 2005, The preferential initiation of dynamic recrystallization (DRX) at triple junctions (TJs) in stainless steel polycrystals was investigated in compression at 1123 K to 1323 K at a strain rate of 2 x 10(4) s(-1). Nucleation appeared at TJs at strains as low as 0.1. This strain is only about 1/5 to 1/2 of the peak strain at which DRX is conventionally believed to occur extensively Furthermore, DRX nucleation was not observed to take place at grain boundaries or in the matrix at this strain. The probability of DRX nucleation at TJs increased monotonically with strain and temperature. It also depended on the angle, V, between the compression axis and the sliding boundary. That is, when the angle, V, approaches 45 degrees, the probability of DRX nucleation at TJs is higher. These results reveal the important role of grain-boundary sliding (GBS) on DRX nucleation at TJs. It should also be noted that more than 90% of the grains nucleated at TJs were twins. Such dynamic twinning suggests that the essential DRX nucleation mechanism is twinning.
Scientific journal, English - Mechanisms of High Temperature Deformation and Extended Elongation of Mg single crystals
H. Miura; T. Sakai; H. Nogawa; Y. Watanabe; S. Miura; J. J. Jonas
Philos. Mag, 85, 3553-3565, 2005
Scientific journal, English - Superplasticity in a 7055 aluminum alloy processed by ECAE and subsequent isothermal rolling
I Nikulin; R. Kaibyshev; T. Sakai
Mater. Sci. Engin, A, 407, 62-70, 2005, Peer-reviwed
Scientific journal, English - Grain-Size Dependence of Microstructural Evolution and Mechanical Behavior during High-Temperature Deformation of Mg and Mg Alloy
H. Miura; X. Yang; J. Xing; T. Sakai
Proceedings of the 1st Asian Symposium on Magnesium Alloys, 77-80, 2005
International conference proceedings, English - Effect of pressing temperature on fine-grained structure formation in 7475 aluminum alloy during ECAP
A Goloborodko; O Sitdikov; R Kaibyshev; H Miura; T Sakai
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ELSEVIER SCIENCE SA, 381, 1-2, 121-128, Sep. 2004, The effect of pressing temperature on microstructural development under ECAP conditions was studied in an as-cast 7475 aluminum alloy at temperatures from 523 to 673 K. The samples were pressed by using route A up to strains of 12. New equiaxial grains with high angle boundaries (HABS) start to be formed after three passes and then gradually developed with repeated ECAP, finally, followed by fully development of a new fine-grained structure. The average (sub)grain size tends to increase and the aspect ratio decreases with increasing pressing temperature. The misorientation distribution of strain-induced dislocation boundaries shows a single peak type at low angle misorientations until second pass and then gradually shifts to higher angles with increasing of strain. Increase in pressing temperature retards the transformation kinetics from low angle boundaries to high angle ones, while the fraction of the latter as well as the average misorientation approach a same saturation value irrespective temperature in high strain. The mechanism of ultra-fine grain formation during ECAP is discussed. (C) 2004 Elsevier B.V. All rights reserved.
Scientific journal, English - Grain fragmentation in a coarse-grained 7475 Al alloy during hot deformation
O Sitdikov; T Sakai; A Goloborodko; H Miura
SCRIPTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 51, 2, 175-179, Jul. 2004, Peer-reviwed, Grain refinement taking place in a coarse-grained 7475 Al alloy was studied in hot multidirectional compression. The structural changes are characterized by grain fragmentation due to frequent development of microshear bands in various directions, followed by increase in their number and misorientation and finally evolution of new grains at high strains. (C) 2004 Published by Elsevier Ltd. on behalf of Acta Materialia Inc.
Scientific journal, English - Effect of pass strain on grain refinement in 7475 Al alloy during hot multidirectional forging
O Sitdikov; T Sakai; A Goloborodko; H Miura; R Kaibyshev
MATERIALS TRANSACTIONS, JAPAN INST METALS, 45, 7, 2232-2238, Jul. 2004, Effect of pass strain (Deltaepsilon) on grain refinement was studied in multidirectional forging (MDF) of a coarse-grained 7475 At alloy at 490degreesC under a strain rate of 3 x 10(-4)S(-1). Samples of rectangular shape were deformed up to accumulated strains of around 6 with subsequent changes in loading direction 90degrees from pass to pass. The pass strains in each compression (Deltaepsilon) were 0.4 and 0.7. The cumulative flow curves integrated by each compression exhibit significant work softening just after yielding, followed by apparent steady state plastic flow at high strains. Structural changes were characterized by grain fragmentation due to frequent development of deformation and/or microshear bands followed by full evolution of new fine grains in the original grains. Increasing Deltaepsilon accelerates significantly the kinetics of grain refinement, leading to more clear reduction of flow stresses at moderate to high strains. MDF of Deltaepsilon = 0.7 results finally in formation of a finer grained structure with an average size of around 7.5 mum at strains of above 3.5, while, the processing with Deltaepsilon = 0.4 develops a slightly coarser grain structure at higher strain of about 6. The effect of MDF on new grain evolution and the mechanisms of grain refinement are discussed in details.
Scientific journal, English - 高強度アウミニウム合金の高温変形中の回復と再結晶
酒井拓
日本軽金属蒲原工場技術センター講演会資料, Mar. 2004
Japanese - Preferential nucleation of dynamic recrystallization at triple junctions
H Miura; T Sakai; H Hamaji; JJ Jonas
SCRIPTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 50, 1, 65-69, Jan. 2004, Peer-reviwed, The preferential nucleation of dynamic recrystallization (DRX) was investigated in copper polycrystals deformed in compression at 873 K and a true strain rate of 2.9 x 10-(4) s (-1). DRX nucleation started preferentially at triple junctions (TJs) at strains of 0.02-0.04, while the peak strain in the flow curve was about 0.08. The number of DRX nuclei at the TJs increased linearly with strain. At a strain of 0.04, DRX was initiated at about 40% of the TJs. However, nucleation was difficult when the TJ contained a twin boundary. It was also noted that most of the nuclei possessed a twin (Sigma3) relation with respect to its parent grain. This is one of the essential features of discontinuous DRX in copper. DRX nucleation at TJs and twin formation are discussed in relation to grain-boundary sliding, grain-boundary migration, and misorientation angle. (C) 2003 Published by Elsevier Ltd. on behalf of Acta Materialia Inc.
Scientific journal, English - High-Angle Boundary Development under Severe Large Deformation of BCC/FCC Stainless Steels (Invited)
T. Sakai; K. Usui; T. Koba; H. Miura; A. Belyakov
Proceedings of 2 nd International Symposium on Ultrafine Grained Structure (ISUGS2), (Geelong, Australia), CDROM, (Inst. of Materials Engineering Australasia Limited),, 2004
English - Development of Ultra-Fine Grains by Severe Plastic Deformation of Copper with Fine Precipitates
H. Miura; T. Sakai
Proceedings of 2 nd International Symposium on “Ultrafine Grained Structure (ISUGS2), (Geelong, Australia), CDROM, (Inst. of Materials Engineering Australasia Limited),, 2004
English - Microstructural Evolution during Severe Deformation in Austenitic Stainless Steel with Second Phase Particles,
H. Miura; H. Hamaji; T. Sakai
Nanomaterials by Severe Plastic Deformation (NanoSPD2), ed. M. Zehetbauer and R. Z. Valief, Wiley-VCH Weinheim, 375-380, 2004
International conference proceedings, English - On annealing Mechanisms Operating in Ultra Fine-Grained Alloys,
T. Sakai; H. Miura; A. Belyakov; K. Tsuzaki
Nanomaterials by Severe Plastic Deformation (NanoSPD2), ed. M. Zehetbauer and R. Z. Valief, Wiley-VCH Weinheim, 780-785, 2004
International conference proceedings, English - Fe-32Ni合金の粒界三重点おける動的再結晶の発現に及ぼすひずみ速度と温度の影響
Sutandyo Andiawarwanto; 三浦博己; 酒井拓
鉄と鋼, 90, 257-262, 2004
Scientific journal, Japanese - Microstructural Control Due to Continuous and Discontinuous Dynamic Recrystallization (Invited),
Taku Sakai
ICPNS’2004-Proceedings of the 4th Int’l Conf. on Physical and Numerical Simulation of Materials Processing, (Shanghai, China, 2004): CDrom, ed by J. T. Niu, 2004
International conference proceedings, English - Nucleation of Dynamic Recrystallization at Grain Boundaries in Copper Bicrystals,
H. Miura; T. Sakai; R. Mogawa; G. Gottstein
Scripta Materialia,, 51, 671-6765, 2004
Scientific journal, English - 析出強化Cu-Cr合金の強ひずみ加工による超微細粒組織形成とその特性
三浦博己; 酒井拓
銅と銅合金, 日本伸銅協会, 43, 1, 56-60, 2004
Scientific journal, Japanese - New Grain Formation in a Coarse-Grained 7475 Al Alloy during Severe Hot Forging
O. Sitdikov; T. Sakai; A. Goloborodko; H. Miura; R. Kaibyshev
Materials Science Forum, 467-470, 421-426, 2004
English - Grain Refinement in Magnesium Alloy AZ31 during Hot Deformation
X. Yang; J. Xing; H. Miura; T. Sakai
Materials Science Forum, 467-470, 531-536, 2004
Scientific journal, English - Dynamic Recrystallization at Grain Boundaries in Copper Bicrystals
H. Miura; T. Sakai; R. Mogawa; G. Gottstein
Materials Science Forum, 467-470, 1211-1216, 2004
Scientific journal, English - Grain refinement in high strength aluminum alloy during severe hot deformation
A. Goloborodko; O. Sitdikov; R. Kaibyshev; H. Miura; T. Sakai
Modern Science and Technology 2004 (IWMST2004), Kitami Univ, 364-367, 2004
International conference proceedings, English - Ultra-fine grain formation in BCC/FCC Stainless Steels during Severe Large Forging
T. Sakai; H. Miura; K. Usui; T. Koba
Evolution of Deformation Microstructures in 3D, Eds. By G. Gunlach et al., Riso National Lab., 509-514, 2004
International conference proceedings, English - Temperature Effect on Deformation Microstructures in Austenite,
A. Belyakov; T. Tsuzaki; H. Miura; T. Sakai
Advanced Structural Steels (ICASS2004), Shanghai (2004),, 830-833, 2004
International conference proceedings, English - Cyclic Creep and Fracture Behavior of Cu-SiO2 Bicrystals with Twist Boundary
H. Miura; Y. Ito; T. Sakai; M. Kato
Materials Science Eng. A, 387-389, 522-524, 2004
English - Mg単結晶の超塑性挙動とその結晶方位依存性
三浦博己; 楊続躍; 酒井拓; 野川久史; 渡辺義見; 三浦誠司
日本金属学会講演概要集（第135回秋期講演大会）, 486, 2004
Research society, Japanese - 析出強化Cu-Fe-Cr合金の強ひずみ加工による微視組織の発達
三浦博己; 瀬川泰三; 酒井拓
第44回銅及び銅合金技術研究会講演概要集, 49-50, 2004
Research society, Japanese - アルミニウム合金の高温変形中の回復・再結晶
酒井拓
鳥取県地域新生コンソシアム第2回研究会，組織制御委員会資料, Nov. 2003
Japanese - Superplasticity in a 7055 aluminum alloy subjected to intense plastic deformation
R Kaibyshev; T Sakai; Nikulin, I; F Musin; A Goloborodko
MATERIALS SCIENCE AND TECHNOLOGY, MANEY PUBLISHING, 19, 11, 1491-1497, Nov. 2003, Peer-reviwed, Superplasticity in a 7055 aluminum alloy subjected to intense plastic straining through equal channel angular extrusion (ECAE) was studied in tension over a range of strain rates from 1(.)4 x 10(-5) to 5(.)6 x 10(-2) s(-1) in the temperature interval 300 - 450degreesC. The alloy had a grain size of similar to1 mum. A maximum elongation to failure of similar to 750% occurred at a temperature of 425degreesC and an initial strain rate of 5(.)6 x 10(-4) s(-1), with a strain rate sensitivity coefficient m of about 0(.)46. The highest m value was similar to0(.)5 at a strain rate of 1(.)4 x 10(-3) s(-1) and Tgreater than or equal to425degreesC. Moderate superplastic properties with a total elongation of about 435% and m of similar to0(.)4 were recorded in the temperature interval 350-400degreesC; no cavitation was found. It was shown that the main feature of superplastic behaviour of the ECAE processed 7055 aluminum alloy is a low yield stress and strong strain hardening during the initial stages of superplastic deformation. Comparing the present results with the superplastic behaviour of the 7055 Al subjected to thermomechanical processing (TMP), the highest tensile elongation in the ECAE processed material occurred at lower temperatures because ECAE produces a finer grained structure.
Scientific journal, English - 連鋳アルミニウム合金7475の結晶粒微細化加工処理，
酒井拓
鳥取県地域新生コンソシアム第１回研究会，組織制御委員会資料, Sep. 2003
Japanese - Deformation and fracture of CU-SiO2 bicrystals with [011] twist boundaries
H Miura; T Sakai; H Toda
ACTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 51, 16, 4707-4717, Sep. 2003, Peer-reviwed, Several kinds of Cu-SiO2 bicrystals having [011] twist boundaries with different misorientation angles were tensile tested at various temperatures from 473-1023 K at strain rates from 4.2 X 10(-5)-4.2 x 10(-3) s(-1) in vacuum. Most of bicrystals fractured intergranularly. The grain-boundary strength and fracture behavior of the Cu-SiO2 bicrystals strongly depended on the grain-boundary character, temperature and strain rate. As the misorientation angle or grain-boundary energy increases, grain-boundary fracture takes place more easily at lower temperatures with lower fracture stresses. Furthermore, fracture stress and elongation to fracture decrease almost monotonically with increasing temperature and decreasing strain rate. The observed grain-boundary character and test condition dependence of grain-boundary strength can be understood reasonably by considering the occurrence of stress-concentration sites around the grain-boundary SiO2 particles to form voids and cracks caused by grain-boundary sliding. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Scientific journal, English - 銅の動的再結晶に及ぼす粒界と分散粒子の影響
三浦博己
北海道大学大学院工学研究科物質工学専攻講演会概要, Jun. 2003
Japanese - Strain-rate effect, on dynamic recrystallization at grain boundary in Cu alloy bicrystal
H Miura; M Ozama; R Mogawa; T Sakai
SCRIPTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 48, 10, 1501-1505, May 2003, Peer-reviwed, The strain-rate dependence of the preferential occurrence of dynamic recrystallization (DRX) at grain boundary was investigated at 1023 K using orientation controlled Cu-Si bicrystals. Preferential DRX nucleation at the grain boundary was observed at all the strain rates. However, such preference of DRX nucleation at the grain boundary became less significant as the strain rate became higher. The strain-rate dependence of DRX nucleation at grain boundary will be discussed in relation to grain-boundary sliding, grain-boundary faceting and grain-boundary migration. (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.
Scientific journal, English - Grain refinement in as-cast 7475 aluminum alloy under hot equal-channel angular pressing
A Goloborodko; O Sitdikov; T Sakai; R Kaibyshev; H Miura
MATERIALS TRANSACTIONS, JAPAN INST METALS, 44, 4, 766-774, Apr. 2003, Peer-reviwed, Microstructural evolution taking place during equal channel angular pressing (ECAP) was studied in an as-cast 0.16%Zr modified 7475 aluminum alloy at a temperature of 673 K. The structural changes are characterized by development of deformation bands due to large strain inhomogeneity occurring through the ECAP die. Repeated deformation leads to an increasing of number and misorientation angle of the boundaries of deformation bands, finally followed by formation of new fine grains at high strains. The misorientation angle distribution for newly developed boundaries shows a single peak type at relatively low misorientations in low strain and changes to a bimodal distribution with two peaks at low and high misorientations in moderate strain. Pressing to a strain of 12 leads to a full development of new grains surrounded by medium to high angle boundaries with an average size of about 1.7 mum. It is concluded that grain refinement occurs by a deformation-induced continuous reaction, that is essentially similar to continuous dynamic recrystallization.
Scientific journal, English - Effect of initial microstructures on grain refinement in a stainless steel by large strain deformation
A Belyakov; K Tsuzaki; H Miura; T Sakai
ACTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 51, 3, 847-861, Feb. 2003, Peer-reviwed, Initial grain size effect on submicrocrystalline structure evolution was studied in multiple compressions of a 304 stainless steel at 873 K (0.5T(m)). Four sets of specimens with different initial microstructures were used, i.e. annealed samples with grain sizes of D-0 = 15 and 2.2 mum, and dynamically recrystallised ones with D-0 = 3.5 and 1.5 mum. The new ultra-fine-grains (D = 0.25 mum) develop as a result of a continuous increase in the misorientations between the subgrains that evolved during deformation. In the samples with D-0 less than or equal to 3.5 mum, the fraction of the strain-induced high-angle boundaries increases rapidly to more than 60% with a straining to about 1.5. On the other hand, their fraction does not exceed 20% at epsilon = 1.5 in the sample with D-0 = 15 mum. The latter needs much more straining to around 6 to obtain 60% of high-angle (sub)grain boundaries. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.
Scientific journal, English - Dynamic evolution of new grains in magnesium alloy AZ31 during hot deformation
XY Yang; HM Miura; T Sakai
MATERIALS TRANSACTIONS, JAPAN INST METALS, 44, 1, 197-203, Jan. 2003, Peer-reviwed, Dynamic grain evolution of a magnesium alloy AZ31 was studied in compression at 673 K (0.73T(m)) by optical and SEM/OIM microscopy. The flow curve shows rapid hardening accompanied by a stress peak at a relatively low strain (epsilon(p) = 0.12), followed by strain softening and then a steady state flow stress at high strains, Fine grains evolved at corrugated grain boundaries at around epsilon(p) and developed rapidly during strain softening. finally leading to a full structure of equiaxed fine grains. Such characteristics of new grain evolution and flow behavior are apparently similar to those in conventional, i.e. discontinuous. dynamic recrystallization (DRX). On the other hand, kink bands Acre observed frequently near corrugated grain boundaries and also in gram interiors, even around epsilon(p). The misorientation of the boundaries of the kink bands increases rapidly during strain softening and approaches it saturation value of around 43 at high strains. The average size of the regions fragmented by kink bands is almost the same a, that of the ne grains. It is concluded, therefore, that new grain evolution in this alloy is controlled by a deformation-induced continuous reaction, i.e. continuous DRX.
Scientific journal, English - Dynamic Nucleation of new grains in a Magnesium Alloy during Hot Deformation,
X. Yang; H. Miura; T. Sakai
Mater. Sci. Forum, 419-422, 515-520, 2003
Scientific journal, English - Dynamic Recrystallization Based on Twinning in Coarse-Grained Magenisium,
O. Sitdikov; K. Kaibyshev; T. Sakai
Mater. Sci. Forum, 419-422, 521-526, 2003
English - Continuous Dynamic Recrystallization in Magnesium Alloy,
A. Galiyev; K. Kaibyshev; T. Sakai
Mater. Sci. Forum,, 419-422, 509-514, 2003
English - Grain Refinement of an As-Cast 7045 Aluminum Alloy during Hot Compression,
R Kaibyshev; O. Sitdikov; A. Goloborodko; T. Sakai
Materials Science and Engineering, 344, 348-356, 2003
English - Grain Boundary Sliding and Grain Refinement in As-Cast 7475 Aluminum Alloy under Hot Deformation, in Hot Deformation of Aluminum Alloys III
O. Sitdikov; A. Goloborodko; R. Kaibyshev; T. Sakai
Eds. Z. Jin, A. Beaudoin, T. A. Bieler and B. Radhakrishnan, TMS, 61-70, 2003
English - Static Recrystallization of SiO2 Particle Containing [011]<100> Copper Single Crystals
H. Miura; T. Sakai; A. Belyakov; G. Gottstein; M. Crumbach; J. Verhasselt
Acta Materialia, 51, 1507-1515, 2003, Peer-reviwed - 鉄鋼の動的再結晶と微細粒組織制御（学術功績賞受賞記念特別講演）
酒井拓
ふえらむ（日本鉄鋼協会会報), 8, 571-574, 2003, Peer-reviwed
Scientific journal, Japanese - Initial Grain Size Effect of Dynamic Recrystallization of Magnesium Alloy AZ31,
X. Yang; H. Miura; T. Sakai
Materials Science Forum, (eds. T. Chandra, J. M. Torralba and T. Sakai, THERMEC’2003, (Trans Tech Publ.)), 426-432, 611-616, 2003, Peer-reviwed
Scientific journal, English - Grain Refinement in as-cast 7475 Al Alloy under Hot Multiaxial Deformation
O. Sitdikov; A. Goloborodko; H. Miura; R. Kaibyshev; T. Sakai
Materials Science Forum, 426-432, 381-386, 2003, Peer-reviwed
Scientific journal, English - Temperature Effect on Microstructure Development in 7475 Aluminum Alloy during ECAP
A. Goloborodko; O. Sitdikov; H. Miura; R. Kaibyshev; T. Sakai
Materials Science Forum, 426-432, 321-326, 2003, Peer-reviwed
Scientific journal, English - Evolution of Grain boundaries and Subboundaries in Stainless Steel during Dynamic Recrystallization
A. Belyakov; K. Tsuzaki; H. Miura; T. Sakai
Materials Science Forum, 426-432, 1005-1010, 2003, Peer-reviwed
Scientific journal, English - Strain Rate Dependence of Dynamic Twin Nucleation at Triple Junction in Copper
H. Miura; S. Andiarawanto; T. Sakai
Materials Science Forum, 426-432, 4387-4392, 2003, Peer-reviwed
Scientific journal, English - Ferrite Refinement through Transformation from a Dynamically Recrystallized IF Steel,
S. Kato; A. Mori; H. Miura; T. Sakai
Thermomechanical Processing: Mechanics, Microstructure & Control, eds. E.J. Palmiere, M. Mahfoul and C. Pinna, The Univ. Sheffield, 17-21, 2003
English - 析出強化Cu-Fe合金の高温加工性と粒界強度
三浦博己; 酒井拓
銅と銅合金, 日本伸銅協会, 42, 1, 6-11, 2003, Peer-reviwed
Scientific journal, Japanese - 銅の高温強度と組織制御に及ぼす整合・非整合析出粒子の影響（2003年度銅及び銅合金研究会論文賞）
三浦博己; 酒井拓
銅と銅合金, 日本伸銅協会, 42, 1, 87-92, 2003, Peer-reviwed
Scientific journal, Japanese - Strain Rate Effect of Dynamic Nucleation at Triple Junction during High-Temperature Deformation in a Copper Tricrystal
S. Andiarwanto; H. Miura; T. Sakai
Mater. Trans., 44, 2213-2219, 2003, Peer-reviwed
Scientific journal, English - Temperature Dependence of Cyclic Creep Behavior of a Cu-SiO2 Bicrystal with a [011] 20 Twist Boundary,
H. Miura; T. Sakai; M. Kato
Acta Materialia, 51, 20, 6163-6168, 2003, Peer-reviwed
Scientific journal, English - The role of grain boundary sliding in microstructural evolution during superplastic deformation of a 7055 aluminum alloy
R Kaibyshev; A Goloborodko; F Musin; Nikulin, I; T Sakai
MATERIALS TRANSACTIONS, JAPAN INST METALS, 43, 10, 2408-2414, Oct. 2002, The microstructure evolution in a 7055 aluminum alloy subjected to thermomechanical processing (TMP) was studied at 450degreesC and (epsilon) over dot = 1.7 x 10(-3) s(-1) at which the material exhibits super-plastic behavior with a total elongation of 720% and the coefficient m = 0.58. Partially recrystallized initial structure of the as-processed 7055 Al consisted of bands of recrystallized grains with a mean size of 11 mum alternating with bands of recovered subgrains with a mean size of 2 mum. The true stress-true strain curve exhibits a well-defined peak stress, followed by gradual strain softening. The coefficient of strain rate sensitivity, In, remains unchanged at epsilon less than or equal to 1 and tends to decrease with strain at epsilon > 1. The initial microstructure persists near the peak strain. Following strain leads to evolution of initial partially recrystallized structure into uniform fully recrystallized structure due to occurrence of continuous dynamic reactions, i.e. continuous dynamic recrystallization (CDRX). The data of microstructural observation and misorientation analysis show that low-angle boundaries (LAB) gradually convert to high-angle boundaries (HAB) resulting in an extensive flow softening. It was shown that grain boundary sliding (GBS) provides superplastic flow at all strains. Concurrently, GBS plays an important role in the dynamic evolution of new grains facilitating conversion of LABs to HABs.
Scientific journal, English - Temperature dependence of fatigue-fracture-mode change in Cu-SiO2 alloy
H Miura; T Sakai; M Kato
INTERNATIONAL JOURNAL OF FATIGUE, ELSEVIER SCI LTD, 24, 9, 943-948, Sep. 2002, Copper polycrystals, single crystals and bicrystals with dispersed spherical SiO2 particles were cyclically deformed at temperatures between ambient temperature and 673 K. All the crystals showed typical cyclic creep behavior. Though the polycrystals tended to show longer life than that of the single crystals at lower temperatures under higher stress amplitude, the life became shorter than that of the single crystals, especially at higher temperatures under applied low stress amplitude. The stress amplitude, where the life of the polycrystal becomes shorter than that of the single crystal, became lower as the temperature increased. At such a stress amplitude (transient stress amplitude), dominant cracking and propagation mode changed from transgranular to intergranular. The fracture mode of the bicrystals also changed sharply at the critical stress amplitude from transgranular to intergranular with increasing temperature. The observed fracture-mode change at the critical stress amplitude is discussed in relation to grain-boundary sliding and grain-boundary cracking. (C) 2002 Elsevier Science Ltd. All rights reserved.
Scientific journal, English - Continuous recrystallization in austenitic stainless steel after large strain deformation
A Belyakov; T Sakai; H Miura; R Kaibyshev; K Tsuzaki
ACTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 50, 6, 1547-1557, Apr. 2002, Static restoration mechanisms operating during annealing were studied in a 304 steel with strain-induced submicron grain structures. The initial microstructure with an average grain size of about 0.3 mum was developed by large strain deformation at 873 K. Early annealing leads to a full relaxation of high internal stresses associated with non-equilibrium strain-induced grain boundaries, while their boundary misorientations and the average grain size barely change. Further annealing results in a transient recrystallization followed by a normal grain growth. The average grain boundary misorientation increases up to around 45degrees in the former and becomes constant in the latter. This is associated with the change in the grain boundary misorientation distribution from a characteristic strain-induced one to a near random distribution corresponding to a fully recrystallized state. The annealing processes operating in the strain-induced fine grains take place homogeneously in the whole matrix and can be called continuous recrystallization. (C) 2002 Published by Elsevier Science Ltd on behalf of Acta Materialia Inc.
Scientific journal, English - Cu-SiO2分散強化合金双結晶の高温疲労と粒界破壊
三浦博己; 柳下良寛; 酒井拓
日本金属学会講演概要集（第130回春期大会）, 248, Mar. 2002
Japanese - Cu-SiO2分散強化合金の中間温度域における疲労破壊とその粒界方位依存性
森永真行; 三浦博己; 酒井拓
日本金属学会講演概要集（第130回春期大会）, 264, Mar. 2002
Japanese - 銅多結晶の粒界三重点おける動的再結晶挙動
Sutandyo Andiawarwant; 三浦博己; 酒井拓
日本金属学会講演概要集（第130回春季大会）, 263, Mar. 2002
Japanese - 析出強化オーステナイト系ステンレス鋼の強ひずみ加工
浜地春佳; 三浦博己; 酒井拓
日本鉄鋼協会第143回春期講演大会, Mar. 2002
Japanese - Preferential dynamic nucleation at triple junction in copper tricrystal during high-temperature deformation
H Miura; S Andiarwanto; K Sato; T Sakai
MATERIALS TRANSACTIONS, JAPAN INST METALS, 43, 3, 494-500, Mar. 2002, Peer-reviwed, Preferential nucleation of dynamic grains at triple junction (TJ) was investigated in copper tricrystal during high-temperature deformation, The nucleation of the dynamic grains at the TJ was observed at much lower strain than the peak strain where dynamic recrystallization (DRX) extensively took place. Further straining caused the incremental nucleation of dynamic grains on sliding grain boundaries accompanied by grain-boundary migration and serration. This, occur-red also at relatively lower strain than the peak strain. The DRX grains evolved to the most area of the tricrystal when deformed to about the peak strain. The observed preferential nucleation of DRX grains at the TJ was considered with relation of stress and deformation concentration there induced by folding and gram-boundary, sliding.
Scientific journal, English - EBSP による粒界三重点での動的再結晶挙動の解析
三浦博己; 酒井拓
バウンダリー, 18, 11-12, 2002
Scientific journal, Japanese - 動的再結晶
三浦博己
鉄鋼便覧第4 版(追補分CD-ROM 版), (分担), 2002
English - AZ31マグネシウム合金の高温変形と微細粒組織の生成
楊続躍; 三浦博己; 酒井拓
軽金属, 52, 318-323, 2002
Scientific journal, Japanese - Dynamic Recrystallization and Texture Develop- ment in a Magnesium Alloy AZ31 at High Temperature
X. Yang; H. Miura; T. Sakai
Light Metals 2002 Metaux Lergers (Including the McQueen Symposium), d., T. Lewis, TMS-CIM,, 867-878, 2002, Peer-reviwed
International conference proceedings, English - 銅三重結晶の粒界三重点おける優先的動的再結晶，
Sutandyo Andiawarwant; 三浦博己; 酒井拓
日本金属学会誌, 66, 760-766, 2002
Japanese - Twin Nucleation at Triple Junction during Hot Deformation of Copper Polycrystal
Hiromi Miura; Haruka Hamaji; Taku Sakai
Materials Science Forum, 408-412, 755-760, 2002
English - Dynamic Recrystallization at Triple Junction during High-Temperature Deformation in Copper Tricrystal,
Sutandyo Andiarwanto; H. Miura; T. Sakai
Materials Science Forum, 408-412, 761-766, 2002
English - Continuous Dynamic Recrystallization in a Superplastic 7075 Aluminum Alloys,
X. Yang; H. Miura; T. Sakai
Mater. Trans.,, 43, 2400-2407, 2002
Scientific journal, English - マグネシュウム合金AZ31の動的再結晶に及ぼす初期結晶粒径の影響，
楊続躍; 三浦博己; 酒井拓
日本金属学会講演概要集（第131回秋期大会）, 459, 2002
Japanese - Microstructure and deformation behaviour of submicrocrystalline 304 stainless steel produced by severe plastic deformation
A Belyakov; T Sakai; H Miura
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, ELSEVIER SCIENCE SA, 319, 867-871, Dec. 2001, Peer-reviwed, The deformation behaviour and structural changes in a 304-type stainless steel were studied in uniaxial compression at temperatures of 873-1073 K (0.5-0.6 T-m) and under strain rates from 10(-4) to 10(-2) s(-1). The starting material. with an initial grain size of approximate to0.3 mum, was produced by multiple warm deformation passes. changing of the loading direction from pass to pass. At high temperature, the resulting fine-grained steel has a low dislocation density and steady-state flow stresses lower than that of an annealed coarse-grained steel. Moreover. the strain rate sensitivity of the fine-grained material reaches high values, up to 0.3, which clearly differs from that of approximate to0.1-0.2 for the coarse-grained steel. At room temperature, the initially fine-grained steel has higher hardness after warm deformation than the conventional steel. (C) 2001 Elsevier Science B.V. All rights reserved.
Scientific journal, English - Superplastic behavior of a 7055 aluminum alloy
R Kaibyshev; T Sakai; F Musin; Nikulin, I; H Miura
SCRIPTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 45, 12, 1373-1380, Dec. 2001, It is shown that a high strength 7055 aluminum alloy with partially recrystallized initial structure exhibits superplastic behavior in the temperature interval 400-490 degreesC within a wide strain rate range from 8.3 x 10(-5) to 3.3 x 10(-2) s(-1). Maximum total elongation of about 960% and strain rate sensitivity coefficient, m, of 0.6 were obtained at a temperature of 450 degreesC and a strain rate of 3.3 x 10(-4) s(-1). (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.
Scientific journal, English - 熱間，温間加工域における微細粒組織の生成と制御
酒井拓
NKK中央研究所招待セミナー資料, Nov. 2001
Japanese - Cu-SiO2分散強化合金の疲労とその温度依存性
三浦博己; 酒井拓
日本伸銅協会講演概要集, Nov. 2001
Japanese - Influence of deformation temperature on microstructure evolution and static recrystallization of polycrystalline copper
AM Wusatowska-Sarnek; H Miura; T Sakai
MATERIALS TRANSACTIONS, JAPAN INST METALS, 42, 11, 2452-2459, Nov. 2001, Peer-reviwed, Static recrystallization was studied in warm and hot deformed polycrystalline copper (99.99%). Samples were compressed to a strain of 0.25 at 573 K and 723 K at a strain rate of 2 x 10(-1) s(-1), quenched in water, and subsequently isothermally annealed at 673 K. Static recrystallization kinetics were found to be faster in samples hot-deformed at 723 K in spite of the lower level of stored strain energy. In all cases nucleation at the early stages of annealing takes place by bulging of serrated grain boundaries. Deformation at 723 K introduces higher orientation gradients evolved along serrated grain boundaries than those at 573 K, It is shown that static recrystallization is controlled not only by the level of stored strain energy, but also by the specific features of sub-grain structures formed in local regions.
Scientific journal, English - Grain refinement in copper under large strain deformation
A Belyakov; T Sakai; H Miura; K Tsuzaki
PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES, TAYLOR & FRANCIS LTD, 81, 11, 2629-2643, Nov. 2001, Peer-reviwed, Structure evolution taking place in pure polycrystalline copper was studied in multiple compressions at room temperature. Rectangular samples were compressed with consequent change in the loading direction from pass to pass. The deformation behaviour at high strains of above 2 shows an apparent steady-state flow following a rapid rise in the flow stress at an early stage of deformation. The structural changes are characterized by the evolution of many mutually crossing subboundaries at low to moderate strains, finally followed by the development of very fine grains with medium- to large-angle boundaries at large strains. These new grains are concluded to be evolved by a kind of continuous reaction, that is continuous dynamic recrystallization (DRX). The grains developed under continuous DRX are much finer than expected from the extrapolation of discontinuous DRX data for hot deformation. An average grain size of about 0.2 mum evolved at room temperature is roughly similar to that for subgrains developed at preceding strains.
Scientific journal, English - Static Recrystallization in Austenite Stainless Steel with Submicrocrystalline Microstructure (Invited)
Taku Sakai
Recent Advancement and Future Prospect on Ultra-Fine Grained Steels (ISIJ International Symposium), 39-42, Sep. 2001
English - 銅粒界すべりに及ぼす粒界上液体B2O3粒子の影響
蓮見洋祐; 三浦博己; 酒井拓
日本金属学会講演概要集（第129回秋季大会）, 431, Sep. 2001
Japanese - 銅多結晶中の粒界三重点における動的再結晶挙動と結晶方位
浜地春佳; 三浦博己; 酒井拓
日本金属学会講演概要集（第129回秋季大会）, 484, Sep. 2001
Japanese - Cu-Si合金の動的粒の粒界生成に及ぼすひずみ速度の影響
三浦博己; 小座間政義; 最川亮; 酒井拓
日本金属学会講演概要集（第129回秋季大会）, 485, Sep. 2001
Japanese - マグネシュウム合金AZ31の高温変形下における微細粒組織の形成
楊続躍; 真田昌美; 三浦博己; 酒井拓
日本金属学会講演概要集（第129回秋季大会）, 485, Sep. 2001
Japanese - 粒界三重点おける動的再結晶の発現に及ぼすひずみ速度の影響
Sutandyo Andiawarwant; 三浦博己; 酒井拓
日本金属学会講演概要集（第129回秋季大会）, 484, Sep. 2001
Japanese - On occurence of dynamic recrystallization in 7475 Aluminum Alloy
A. Golobordko; H. Miura; T. Sakai
日本金属学会講演概要集（第129回秋期大会）, 485, Sep. 2001
English - 銅における連続・不連続再結晶
酒井拓; 三浦博己; 高山明大
日本金属学会講演概要集（第129回秋期大会），公募シンポジュウム「超高集積Si半導体デバイス用Al及びCu配線材料開発と周辺技術の展開」, 179, Sep. 2001
Japanese - Continuous and Discontinuous Recrystallization of Copper and 304 Stainless Steel
Taku Sakai
Invited seminar in Ecole de Nationale Superieure des Mines de Saint-Etienne, France, Sep. 2001
English - Temperature dependency of cyclic deformation behavior of Cu-SiO2 single crystal
H Miura; K Kotani; T Sakai
ACTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 49, 16, 3379-3386, Sep. 2001, Peer-reviwed, Copper single crystal with dispersed sphere SiO2 particles were cyclically deformed at the temperatures between 298 K and 673 K. Cu-SiO2 alloy showed longer life compared with pure copper irrespective of temperature and stress amplitude. This would be due to matrix strengthening not only by dispersion but also by development of cell structures in which the dispersed particles behave as their nodes. At higher temperatures, occurrence of stress relaxation around the Cu/SiO2 interface lowered stress-amplitude dependency of slope (Delta epsilon/Delta logN). The observed easy nucleation of fine voids at the Cu/SiO2 interface seemed not to lower the fatigue strength nor shorten the life. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.
Scientific journal, English - 高温加工オーステナイトの回復と再結晶
酒井拓
新日本製鉄八幡技術研究所招待セミナー資料, May 2001
Japanese - Microstructural Evolution during Warm and Hot ECAE in a Midified 7475 Aluminum Alloy
A. Golobordko; H. Miura; T. Sakai
日本金属学会講演概要集（第128回春期大会）, 165, Mar. 2001
English - Fe-20%Cr合金の温間強ひずみ変形に伴う組織変化
古場崇裕; 三浦博己; 酒井 拓
日本金属学会講演概要集（第128回春季大会）, 167, Mar. 2001
Japanese - 鉄鋼の低温変形下の構成式と降伏応力
高村昌弘; 三浦博己; 酒井 拓
日本金属学会講演概要集（第128回春季大会）, 200, Mar. 2001
Japanese - Cu-SiO_2_分散強化合金双結晶の中間温度域疲労における粒界破壊の発現と寿命の低下
伊藤保之; 三浦博己; 酒井 拓
日本金属学会講演概要集（第128回春季大会）, 209, Mar. 2001
Japanese - 低温変形下の構成方程式と降伏応力
酒井 拓
自動車用材料の高速変形に関する研究会成果報告会（日本鉄鋼協会シンポジュウム）, Mar. 2001
Japanese - 大ひずみ加工による微細粒組織の生成過程-連続再結晶と不連続再結晶（依頼講演）
酒井 拓; 三浦博己; A. Belyakov
日本鉄鋼協会討論会「結晶粒超微細化のメカニズム」，材料とプロセス, 14, 3, 470-473, Mar. 2001
Japanese - 低温高速変形下の構成方程式と降伏応力
高村昌弘; 三浦博己; 酒井 拓
自動車用材料の高速変形に関する研究会成果報告書，（武智弘主査），日本鉄鋼協会, 105-119, 2001
Japanese - Fatigue Behavior of Cu-SiO2 Alloy at Elevated Temperatures, Creep & Fracture of Engineering Materials and Structures
H. Miura; T. Sakai
ed. by J. D. Parker, The Inst. of Metals, 29-35, 2001
English - Temperature Dependence of Fatigue Behavior of Cu-SiO2 Bicrystal Having [001] Twist 18 boundary
H. Miura; T. Ooi; T. Sakai
Phil. Mag. Letters, 81, 293-300, 2001, Peer-reviwed
English - Dynamic Recrystallization under Continuous and Discontinuous Reaction (Invited), Recrystallization and Grain Growth
T. Sakai; A. Belyakov; H. Miura
Recrystallization and Grain Growth, eds. G. Gottstein and D. A. Molodov, Springer, 669-682, 2001, Peer-reviwed
International conference proceedings, English - New Grain Formation under Dynamic Recrystallization of Copper, Recrystallization and Grain Growth
A. M. Wusatowska-Sarnek; H. Miura; T. Sakai
eds. G. Gottstein and D. A. Molodov, Springer, 899-904, 2001
English - Dynamic Recrystallization at Triple Junction in Copper Tricrystal, Recrystallization and Grain Growth
H, Miura; Sutandyo Andiarawante; T. Sakai
eds. G. Gottstein and D. A. Molodov, Springer, 905-910, 2001
English - Static Recrystallization in Austenitic Stainless Steel with Subcrystalline Microstructure, Ultrafine Grained Steels (ISUGS 2001)
T. Sakai; H. Miura; A. Belyakov; K. Tsuzaki
eds. S. Takaki and T. Maki, ISIJ, 210-213, 2001
English - Formation of Nanoscale Grains during Intensive Plastic Straining in Ferritic Steels, Ultrafine Grained Steels (ISUGS 2001)
R Kaibyshev; T. Sakai; A. Belyakov; I Kazakulov
eds. S. Takaki and T. Maki, ISIJ, 152-155, 2001
English - Influence of Deformation Temperature on Microstructural Evolution and Static Recrystallization of Poly - crystalline Copper
A. M. Wusatouska-Sarnek; H. Miura; T. Sakai
Materials Transaction, 42, 5501-5508, 2001
English - Superplastic Behavior of a Commercial 7055 Aluminum Alloy
R Kaibyshev; T. Sakai; F. Musin; H. Miura
Scripta Materialia, (in press), 2001
English - Shape Change of Liquid B2O3 Particles Dispersed in Copper Crystals during High Temperature Deformation
H. Miura; T. Sakai
Mater. Sci. Engin.,in press., 2001
English - Microstructure and Deformation Behavior of Submicrocrystalline 304 Stainless Steel Produced by Severe Plastic Deformation
A. Belyakov; T. Sakai; H. Miura
Mater. Sci. Engin., in press., 2001
English - Martensitic Transformation of Iron Particles Embeded in Copper Matrix during Tension in Crystals Previously Deformed on Another Slip Systems
A.M. Wusatouska-Sarnek; T. Sakai; H. Miura
Mater. Sci. Engin., in press, 2001
English - Grain Boundary Distribution Developed in 7475 Aluminum Alloy during Hot Equal- Channel Angular Extrusion
A. Goloborodko; O. Sitdikov; R. Kaibyshev; H. Miura; T. Sakai
J. Mater. Process. Tech., (in press)., 2001
English - Fine Grained Structure Evolution under Superplastic Deformation of Nonrecrystallized Aluminum Alloys
X. Yang; T. Sakai; H. Miura
J. Mater. Process. Tech., (in press), 2001
English - Annealing Behavior of 304 Stainless Steel with Strain Induced Submicron Grain Structure
A. Belyakov; K. Tsuzaki; T. Sakai
J. Mater. Process. Tech., (in press), 2001
English - Modeling the Distribution of Grain Sizes under Dynamic Recrystallization
W. Gao; T. Sakai; H. Miura
J. Mater. Process. Tech., (in press), 2001
English - オーステナイト炭素鋼の高温加工再結晶に及ぼす炭素含有量の影響
守谷直樹; 三浦博己; 酒井拓
材料とプロセス, 15, 2001
Japanese - IF鋼の温間強ひずみ変形に伴う微細粒組織の生成
滝山直樹; 三浦博己; 酒井拓
材料とプロセス, 15, 2001
Japanese - Fatigue Behavior of Cu-SiO2 Alloy at Elevated Temperatures
H. Miura; T. Sakai
29-35, 2001
International conference proceedings, English - Temperature Dependence of Fatigue Behavior of Cu-SiO2 Bicrystal Having [001] Twist 18 °boundary
H. Miura; T. Ooi; T. Sakai
Phil. Mag. Letters, 81, 293-300, 2001, Peer-reviwed
Scientific journal, English - New grain formation under dynamic recrystallization of copper
AM Wusatowska-Sarnek; H Miura; T Sakai; MJ Blackburn
RECRYSTALLIZATION AND GRAIN GROWTH, VOLS 1 AND 2, SPRINGER-VERLAG BERLIN, 899-904, 2001, Evolution of dynamically recrystallized (DRX) grains under warm and hot deformation was investigated in polycrystalline copper. Large orientation gradients are developed near grain boundaries under high values of Zener-Hollomon parameter Z, and conversely small gradients at low Z. Gradients are introduced by boundary sliding and/or shearing at grain or interface boundaries between DRX region and strain hardened matrix. The frequency of thermally activated grain boundary motion as well as the development of local orientation gradients leads to the operation of different mechanisms of DRX nucleation. DRX nucleation and the formation of necklace structures are discussed on the basis of rotation or twinning taking place in the bulged grain boundary.
International conference proceedings, English - Dynamic recrystallization at triple junction in copper tricrystal
H Miura; S Andiarwanto; T Sakai
RECRYSTALLIZATION AND GRAIN GROWTH, VOLS 1 AND 2, SPRINGER-VERLAG BERLIN, 905-910, 2001, Dynamic recrystallization (DRX) at triple junction (TJ) in copper tricrystal during high-temperature deformation was investigated. Preferential nucleation of dynamic grain at the TJ was observed at lower strain (about 1/3) than peak strain where DRX frequently takes place. It is concluded, therefore, the TJ can be a preferential nucleation site for DRX. This result is discussed in relation with occurrence of grain-boundary sliding.
International conference proceedings, English - Continuous and Discontinuous Dynamic Recrystallization
T. Sakai; J.J. Jonas
Plastic Deformation in the Encyclopedia of Materials: Science and Technology, eds. B. Ilshner and M. Meyers, (2001), Elsevier, 7079-7084, 2001
English - Static Recrystallization in Austenitic Stainless Steel with Subcrystalline Microstructure
T. Sakai; H. Miura; A. Belyakov; K. Tsuzaki
Ultrafine Grained Steels (ISUGS 2001), eds. S. Takaki and T. Maki, ISIJ, 210-213, 2001
English - Formation of Nanoscale Grains during Intensive Plastic Straining in Ferritic Steels
R Kaibyshev; T. Sakai; A. Belyakov; I Kazakulov
Ultrafine Grained Steels (ISUGS 2001), eds. S. Takaki and T. Maki, ISIJ, 152-155, 2001
English - Temperature Dependence of Cyclic Deformation Behavior of Cu-SiO2 Single Crystal
H. Miura; K. Kotani; T. Sakai
Acta Materialia, 49, 8, 3379-3386, 2001, Peer-reviwed
English - Shape Change of Liquid B2O3 Particles Dispersed in Copper Crystals during High Temperature Deformation
H. Miura; T. Sakai
Mater. Sci. Engin., A319-321, 756-759, 2001, Peer-reviwed
Scientific journal, English - Martensitic Transformation of Iron Particles Embeded in Copper Matrix during Tension in Crystals Previously Deformed on Another Slip Systems
A.M. Wusatouska-Sarnek; T. Sakai; H. Miura
Mater. Sci. Engin., A319-321, 224-228, 2001, Peer-reviwed
English - Grain Boundary Distribution Developed in 7475 Aluminum Alloy during Hot Equal-Channel Angular Extrusion
A. Goloborodko; O. Sitdikov; R. Kaibyshev; H. Miura; T. Sakai
THERMEC' 2000 - Proceedings International Confer- ence on Processing and Manufacturing of Advanced Materials, (Las Vegas, USA, 2000): CDROM, Section A1, Vol 117/3 “Special Issue: Journal of Materials Processing Technology”, Eds. T. Chandra, K Higashi, C., 2001
International conference proceedings, English - Fine Grained Structure Evolution under Super- plastic Deformation of Nonrecrystallized Aluminum Alloys
X. Yang; T. Sakai; H. Miura
THERMEC'2000 (Las Vegas, USA, 2000): CDROM, Section A1, Vol 117/3 “Special Issue: Journal of Materials Processing Technology”, Eds. T. Chandra et al. (Elsevier Science, UK), 2001
International conference proceedings, English - Annealing Behavior of 304 Stainless Steel with Strain Induced Submicron Grain Structure
A. Belyakov; K. Tsuzaki; H. Miura; T. Sakai
THERMEC'2000, (Las Vegas, USA, 2000):CDROM, Section A1, Vol 117/3 “Special Issue: Journal of Materials Processing Technology”, Eds. T. Chandra et al. (Esevier Science, UK), 2001
English - Modeling the Distribution of Grain Sizes under Dynamic Recrystallization
W. Gao; T. Sakai; H. Miura
THERMEC'2000 (Las Vegas, USA, 2000):CDROM, Section A1,Vol 117/3 “Special Issue: Journal of Materials Processing Technology”, Eds. T. Chandra et al., (Elsevier Science, UK), 2001
English - Fatigue and fracture of Cu-SiO2 bicrystal with a [011] 18° twist boundary at 673K
H. Miura; T. Sakai
Proceedings of international conference of fracture 2001 (ICF10), (Hawaii, USA): CDROM-0301, Eds. K. Ravi-Chandar, B. L. Karihaloo, T. Kishi, R. O. Ritchie, A. T. Yokobori Jr, T. Yokobori, Elsevier Science, UK, 2001
International conference proceedings, English - Effect of Distribution Change of Grain Boundary Particles on Grain Boundary Strength at Elevated Temperature
H, Miura; T. Sakai
Advanced Materials and Processing (PRICM-4), Eds. S. Hanada, Z. Zhong, S. W. Nam and R. N. Wright, (Hawaii, JIM), 2583-2586, 2001
English - Embittlement of Cu [011] symmetric tilt boundaries induced by Sb segregation
R Monzen; T Kuze; O Matsuda; H Miura
PRICM 4: FORTH PACIFIC RIM INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS AND PROCESSING, VOLS I AND II, JAPAN INST METALS, 795-798, 2001, Cu bicrystals with various [011] symmetric tilt boundaries doped with Sb were tensile tested at several temperatures from 77 to 773 K. Their fracture behavior depended sensitively on the misorientation angle, Sb-doping time and testing temperature. Grain boundaries were more embrittled with increasing the Sb-doping time, though its tendency was also dependent on the misorientation. The degree of embrittlement of grain boundaries became weaker as the testing temperature increased up to about 500 K, while it became stronger again at higher temperatures. A strong correlation has been found between the fracture behavior at 77 and 773 K and grain-boundary energy : the higher the grain-boundary energy, the easier the brittle fracture at grain boundaries becomes.
International conference proceedings, English - Nucleation and Microtexture Development under Dynamic Recrystallization of Copper
A. M. Wusatowska-Sarnek; H. Miura; T. Sakai
Mater. Sci. and Engin, A323, 1777-186, 2001
English - 粒界三重点における動的再結晶の発現と多重双晶
三浦博己; Sutandyo Andiawarwant; 酒井 拓
日本金属学会第2回材料集合組織研究会資料，大阪大学, 39-40, Dec. 2000
Japanese - Ultra Fine-Grained Structure Evolution under Large Strain Deformation of Copper
A. Belyakov; T. Sakai; H.Miura; K. Tsuzaki
Abstracts of International Conference on THERMEC2000, USA, 124, Dec. 2000
English - 熱間，温間域における連続再結晶と不連続再結晶（招待講演）
酒井 拓
第2回超微細結晶粒材料研究会資料，立命館大学, Dec. 2000
Japanese - 分散強化Cu-SiO2合金単結晶の疲労と温度依存性
三浦博己; 酒井 拓
日本機械学会第8回機械材料・材料加工技術講演会，M & P 2000概要集, 297-298, Nov. 2000
Japanese - Strain-induced submicrocrystalline grains developed in austenitic stainless steel under severe warm deformation
A Belyakov; T Sakai; H Miura; R Kaibyshev
PHILOSOPHICAL MAGAZINE LETTERS, TAYLOR & FRANCIS LTD, 80, 11, 711-718, Nov. 2000, Strain-induced grain evolution in a 304 type austenitic stainless steel has been studied in multiple compression with the loading direction being changed in each pass. The tests were carried out to total strains above 6 at 873 K (0.5T(m)) at a strain rate of about 10(-3) s(-1). Multiple deformation promotes the rapid formation of many mutually crossing subboundaries because various slip systems operate from pass to pass. The gradual rise in misorientations across dislocation subboundaries with increasing strain finally leads to the evolution of very fine grains with large-angle boundaries. It is concluded that a new grained structure can result From a kind of continuous reaction during deformation, namely continuous dynamic recrystallization. Such deformation-induced grains are characterized by relatively low densities of dislocations, and considerable lattice curvatures developed in their interiors. The latter observations suggest that high elastic distortions are developed in the grain interiors and so such strain-induced grain structures are in a non-equilibrium state.
Scientific journal, English - 超微細粒化304ステンレス鋼の高温変形と動的再結晶
A. Belyakov; 三浦博己; 酒井拓
日本金属学会講演概要集（第127回秋期大会）, 239, Oct. 2000
Japanese - Structure Evolution in Copper during Multiple Deformation at Ambient Temperature
A. Belyakov; T. Sakai; H.Miura; T. Tsuzaki
日本金属学会講演概要集（第127回秋期大会）, 229, Oct. 2000
English - Grain Boundary Distribution Developed in 7475 Aluminum Alloy under Hot ECAE
A. Golobordko; H. Miura; T. Sakai
日本金属学会講演概要集（第127回秋期大会）, 278, Oct. 2000
English - Fe-20%Cr合金の温間強ひずみ変形に伴う組織変化
古場崇裕; 三浦博己; 酒井 拓
日本金属学会講演概要集（第127回秋季大会）, 299, Oct. 2000
Japanese - 銅三重結晶の粒界三重点における優先的動的再結晶の発現（Ⅰ）
Sutandyo Andiawarwant; 三浦博己; 酒井 拓
日本金属学会講演概要集（第127回秋季大会）, 239, Oct. 2000
Japanese - 銅三重結晶の粒界三重点における優先的動的再結晶の発現（Ⅱ）
三浦博己; 佐藤恵一; Sutandyo Andiawarwant; 酒井拓
日本金属学会講演概要集（第127回秋季大会）, 240, Oct. 2000
Japanese - 未再結晶Al合金の超塑性変形における微細粒組織形成のSEM/EBSDその場観察
楊 続躍; 酒井 拓; 三浦博己
日本金属学会講演概要集（第127回秋季大会）, 257, Oct. 2000
Japanese - 普通炭素鋼の低温変形特性に及ぼす炭素含有量の影響
高村昌弘; 盛谷直樹; 三浦博己; 酒井 拓
日本金属学会講演概要集（第127回秋季大会）, 228, Oct. 2000
Japanese - Cu-SiO_2_分散強化合金双結晶の中間温度域における疲労挙動
伊藤保之; 三浦 博己; 酒井拓
日本金属学会講演概要集（第127回秋季大会）, 503, Oct. 2000
Japanese - 動的再結晶粒核生成の動力学モデル
高 維林; 三浦博己; 酒井 拓
日本金属学会講演概要集（第127回秋期大会）, 298, Oct. 2000
Japanese - Grain Size Control due to Dynamic Recrystallization
T. Sakai
Special Seminar in Rautaruuki Steels（Finland）, Sep. 2000
English - 粒界三重点での優先的な動的再結晶粒の形成
三浦博己; 酒井 拓
日本金属学会高温材料設計研究会資料, Aug. 2000
Japanese - Cu-SiO_2_合金単結晶の疲労特性とその温度依存性
三浦博己; 酒井 拓
日本金属学会高温材料設計研究会資料, Aug. 2000
Japanese - Influence of Deformation Temparature on Static Recrystallization
A. Wusatouska-Sarnek; H. Miura; T. Sakai
日本金属学会高温材料設計研究会資料, Aug. 2000
English - 塑性加工に伴う新粒組織の生成機構－連続／不連続再結晶（基調講演）
酒井拓
日本金属学会高温材料設計研究会資料, Aug. 2000
Japanese - Cu-Si合金双結晶の動的再結晶挙動に及ぼすひずみ速度の影響
三浦博己; 小座間政義; 最川亮; 酒井拓
日本金属学会高温材料設計研究会資料, Aug. 2000
Japanese - Fine grained Microstructure Developed in 304 Stainless Steel under Multiple Warm Deformation
A. Belyakov; T. Sakai; H.Miura
The 10th Iketani Conference on Materials Research toward the 21st Century,（Karuizawa）, 60, Jun. 2000
English - 鉄鋼の低温高速変形特性-炭素量の影響
酒井 拓
日本鉄鋼協会「自動車材料の高速変形」研究会資料, Jun. 2000
Japanese - Sliding of copper [001]-twist grain boundaries detected by shear deformation of liquid B2O3 particles on the grain boundaries
H Miura; T Sakai; T Otsuka; R Monzen; S Onaka
ACTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 48, 8, 1959-1966, May 2000, From a Cu-O.O65mass%B solid solution alloy, bicrystals having [001]-twist grain boundaries with various misorientation angles were prepared by the Bridgman method. Cu bicrystals containing B2O3 particles were made from the bicrystals by internal oxidation treatment. The Cu-B2O3 bicrystals were tensile tested at high temperatures, where B2O3 particles become liquid. The amount of grain-boundary sliding was measured from the amount of shear deformation of the liquid B2O3 particles on a sliding grain boundary. Shear deformation of Voids where the B2O3 particles was embedded was also utilized to measure the amount of grain-boundary sliding. The temperature and misorientation-angle dependence of the grain-boundary sliding is discussed for the Cu-B2O3 bicrystals. Since the liquid B2O3 particles easily deform at high temperatures, the measured amount of grain-boundary sliding is considered to reflect the inherent nature of the Cu [001]-twist grain boundaries. Using the present method of measurements, up to 2 mu m grain-boundary sliding can be measured with an accuracy of about 0.1 mu m. (C) 2000 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.
Scientific journal, English - Fine-grained structure formation in austenitic stainless steel under multiple deformation at 0.5 T-m
A Belyakov; T Sakai; H Miura
MATERIALS TRANSACTIONS JIM, JAPAN INST METALS, 41, 4, 476-484, Apr. 2000, Fine-grained structure formation taking place in a 304 type austenitic stainless steel was studied in multiple compression at a temperature of 873 K (0.5T(m)) under a strain rate of about 10(-3) s(-1). The integrating flow curve shows a maximum in flow stress at strains around 1.5 followed by a minor strain softening at cumulative strains beyond 3. The structural changes during deformation can be characterized by the evolution of elongated subgrains with their boundaries as dense dislocation walls at low to moderate strains. These subgrains become more equiaxed and the subboundary misorientations gradually increase with strain, finally leading to the development of fine grained structure with misorientations beyond 20 degrees and an average grain size of about 300 nm. Some of the newly evolved grains contain much lower dislocation densities in their interiors than those evolved at early strains. The mechanisms of such structural development as well as the relationship between microstructures and mechanical properties are discussed in detail.
Scientific journal, English - High-temperature deformation of Cu-SiO2 bicrystals with [011] twist boundaries
H Miura; K Saijo; T Sakai
CREEP AND FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, TRANSTEC PUBLICATIONS LTD, 171-1, 269-276, 2000, C-11-SiO2 bicrystals having [011] twist boundaries with different misorientation angles were tensile tested at various temperatures from 473 to 1073K and at an initial strain rate of 4.2 x 10(-4)s(-1). Most bicrystals fractured intergranularly. As the grain-boundary energy increases, intergranular brittle fracture tended to take place more easily at lower temperatures; the ductility of bicrystals with higher energy boundaries became lower. The elongation to fracture of the intergranularly fractured bicrystals decreased almost monotonically with increasing temperature These grain boundary dependent characteristics of deformation and fracture behavior of the bicrystals could be understood reasonably by considering the difference in easy occurrence of grain-boundary sliding. That is, when grain-boundary sliding takes place, grain-boundary SiO2 particles suppress the sliding, and therefore, stress concentration sites around the particles are formed which promote preferential nucleation sites of voids and cracks. It can be concluded that the easier the saturated grain-boundary sliding occurs, the more brittle the grain boundary becomes.
Scientific journal, English - Modelling the Stress-Strain Curres under Dynamic Recrystallization
W. Gao; T. Sakai; H. Miura
Acta Metallurgca Sinica, 13, 349-358, 2000
English - Substructures and internal stresses developed under warm severe deformation of austenitic stainless steel
A Belyakov; T Sakai; H Miura; R Kaibyshev
SCRIPTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 42, 4, 319-325, Jan. 2000
Scientific journal, English - Dynamic Recrystallization in Uetra-Fine Graineol 304 Sta-ineess Steel
A. Belyakov; H. Miura; T. Sakai
Scripta Materialia, 43, 21-26, 2000
Scientific journal, English - Cyclic deformation behavior of copper single crystals with dispersed SiO2 particles
H. Miura; T. Sakai; H. Mizukiri; M. Kato
SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, TAYLOR & FRANCIS LTD, 1, 2, 125-129, 2000, Cyclic deformation behavior of Cu single crystals with dispersed SiO2 particles were investigated. Even for a small amount of 0.41 vol.% dispersion of SiO2 particles, the cyclic deformation behavior was seen to be clearly different from that of pure Cu. There was longer life and slower clack propagation by the dispersion. This would be due to the homogeneous formation of the dislocation substructure in the Cu-SiO2 sample to prohibit the stress concentration at a point that fastens the clack nucleation. (C) 2000 Elsevier Science Ltd. All rights reserved.
Scientific journal, English - Deformation behavior of 7475 aluminum alloy at high temperatures
R Kaibyshev; O Sitdikov; A Goloborodko; T Sakai
CREEP AND FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, TRANSTEC PUBLICATIONS LTD, 171-1, 355-362, 2000, Deformation behavior of the 7475 aluminum alloy was studied in temperature range T=623-793K by compression test. It has been shown that the 7475 alloy exhibits a threshold behavior. Analysis in terms of threshold stress has shown that there are two characteristic modes of deformation behavior in the power-law regime in the examined temperature range. At normalized strain rate (epsilon)over dotRT/D(1)Gb less than or equal to 1.6.10(13) mol(-1) the value of the stress exponent, n, is equal 4, and at normalized strain rate (epsilon)over dotRT/D(1)Gb greater than or equal to 1.6.10(13) mol(-1) the value of the stress exponent, n, is equal 6. Value of activation energy is close to that for lattice self-diffusion in pure aluminum at temperatures above 763K and close to the value of pipe diffusion at T less than or equal to 723K. Deformation behavior of the 7475 alloy was interpreted in terms of transition from low temperature climb to high temperature one. Two types of temperature dependence of threshold stress was observed in the examined temperature region. Strong temperature dependence with the energy term, Q(o)=130 kJ/mol was revealed at T=743-793K. At T=673-743K the dependence with Q(o)=42 kJ/mol was found. The role of second phase dissolution in threshold behavior of the alloy is considered.
Scientific journal, English - Grain Refinement in a 304 Type Stainless Steel Caused by Multiple Deformation at 0.5Tm
A. Belyakov; T. Sakai; H. Miura
ISIJ International, 40(Supplement), S164-S168, 2000
English - Some Problems in Ultrafine Grained Structures
T. Sakai
Invited lecture in a seminar on "Ultrafine Grained Austenitic Steels"at National Research Institute for Metals,（Tsukuba）, 2000
English - Submicrocrystalline Structures and Internal Distorsion in 304 Type Stainless Steel Produced by Severe Deformation
A. Belyakov; T. Sakai; H.Miura
日本金属学会講演概要集（第126回春期大会），シンポジューム「強ひずみ加工による微細粒組織制御」, 60, 2000
English - 液体分散B_2_O_3_粒子のアスペクト比変化に及ぼすひずみ速度の影響
三浦博己; 酒井拓; 尾中晋
日本金属学会講演概要集（第126回春期大会），シンポジューム「ストラクチャーダイナミックス」, 67, 2000
Japanese - 再結晶粒サイズの分布関数の導出
高 維林; 三浦博己; 酒井 拓
日本金属学会講演概要集（第126回春期大会）, 243, 2000
Japanese - Supral100Al合金の超塑性変形と新粒形成
楊 続躍; 許 請訓; 酒井 拓; 三浦博己
日本金属学会講演概要集（第126回春期大会）, 305, 2000
Japanese - Interrelation between plastic Deformation and Martensitic Transformation of Fe Particles Embeded in Cu Matrix
A. Wusatouska-Sarnek; H. Miura; T. Sakai
日本金属学会講演概要集（第126回春季大会）, 242, 2000
English - Cu-15%Cr複相合金の高温変形
高井和裕; 三浦博己; 酒井 拓; 鈴木洋夫
日本金属学会講演概要集（第126回春季大会）, 302, 2000
Japanese - 熱間加工フェライト鋼の静的再結晶
堺 英雄; 三浦博己; 酒井 拓
日本金属学会講演概要集（第126回春季大会）, 247, 2000
Japanese - Fe-20%Cr合金の高温変形に伴う組織変化
古場崇裕; A.Belyakov; 三浦博己; 酒井 拓
日本金属学会講演概要集（第126回春季大会）, 301, 2000
Japanese - 分散強化Cu-SiO_2_合金粒界の高温強度，
八木和雄; 三浦博己; 酒井 拓
日本金属学会講演概要集（第126回春季大会）, 303, 2000
Japanese - 再結晶・集合組織研究会の活動を終えて
酒井 拓
ふぇらむ（日本鉄鋼協会会報）, 5, 46-47, 2000
Japanese - Microstructural Development under Dynamic Recrystallization of Poly-crystalline Materials（Keynote）
T. Sakai
Thermomechanical Processing of Steels（J. J. Jonas Symposium），eds. S. Yue and E. Essadiqi, TMS-CIM（Montreal）, 47-62, 2000
English - Continuous Recrystallization under Superplasticity of 7075 Aluminum Alloy, Light Metals 2000（Metaux Legers）
T. Sakai; X. Yang; H. Miura
eds. J. Kazadi and J. Masounave, TMS-CIM（Montreal）, 407-418, 2000
English - Fine Grained Structures Evolved under Multiple Warm Deformation, Recrystallization-Fundamental Aspects and Relations to Deformation Microstructure
T. Sakai; H. Miura; A. Belyakov
eds. N. Hansen, et al., Riso National Lab., Denmark, 551-556, 2000
English - Grain Refinement by Warm Multiple Deformation of 304 Stainless Steel
T. Sakai; H. Miura; A. Belyakov; T. Tsuzaki
Proceedings of Inter. Conf. of "Current Status of Theory and Practice of Superplasticity in Materials", The Institute of Metals Superplasticity Problems of the Russian Academy of Sciences,（Ufa）, 10-14, 2000
English - 鉄鋼の変形抵抗
酒井 拓
最新塑性加工要覧第２版（分担），塑性加工学会, 11-12, 2000
Japanese - 動的再結晶による微細粒組織の生成と制御，結晶粒微細化への新アプローチ，
酒井 拓
日本金属学会セミナーテキスト, 83-86, 2000
Japanese - Coherency strains influence on martensitic transformation of gamma-Fe particles in compressed Cu-Fe alloy single crystals
AM Wusatowska-Sarnek; H Miura; T Sakai
JOURNAL OF MATERIALS SCIENCE, KLUWER ACADEMIC PUBL, 34, 22, 5477-5487, Nov. 1999, Single crystals of a Cu-Fe alloy, which contained spherical gamma-Fe particles, were compressed up to shear strain of 0.17 in liquid nitrogen bath. In the process of straining the structural (optical and TEM) observations in as-deformed and post-deformation annealed samples were provided. The substructure of deformed samples was characterized by slightly developed cell structure and lack of distinct layer-like arrangements of dislocations. Three kinds of particles were found: coherent and semi-coherent f.c.c. gamma-Fe and martensiticly transformed b.c.c. alpha-Fe. The critical diameter for coherency loss was found to be 58 nm at the initial stage of deformation decreasing with strain to 50 nm. These values coincided with the theoretical estimations. It was suggested that relaxation of coherency strains around gamma-Fe particles by the generation of interface dislocations might occur prior to the martensitic transformation. This assumption might explain the particle size dependency of martensitic transformation. (C) 1999 Kluwer Academic Publishers.
Scientific journal, English - Microstructure Control by Dynamic Recrystallization: Continuous and Discontinuous Reaction
T. Sakai
Invited lecture in Northeastern University（China）, Oct. 1999
English - 粒界上液体粒子の銅粒界すべりに及ぼす影響
三浦博己; 酒井 拓
結晶性材料の高温強度研究会資料, Aug. 1999
Japanese - Structural Changes Caused by Severe Wram Deformation of a 304 Stainless Steel
A. Belyakov; T. Sakai; H. Miura
結晶性材料の高温強度研究会資料, Aug. 1999
English - 7075アルミニウム合金における連続再結晶と超塑性（招待）
酒井 拓; 楊 続躍; 三浦博己
第97回超塑性研究会資料, May 1999
Japanese - Effect of dispersed liquid B2O3 particles on high-temperature mechanical behavior of copper bicrystals
H Miura; T Sakai; H Tamura; G Gottstein
ACTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 47, 3, 757-768, Feb. 1999, Orientation controlled Cu bicrystals with dispersed B2O3 particles, where B2O3 behaves liquid like at high temperature, were tensile tested at elevated temperatures. The fracture strain tended to decrease with increasing temperature and misorientation angle, and with decreasing strain rate. At lower temperatures where B2O3 behaves like a solid. the occurrence of grain-boundary fracture was understood by the difference of the time constant for saturated grain-boundary sliding to provide stress concentration sites to promote voids and cracks. Furthermore, at higher temperatures where B2O3 behaves liquid-like, the occurrence of grain-boundary fracture was explained by the loss of grain-boundary strength due to the increasing density of the grain-boundary area fraction of liquid particles and/or formation of liquid film at the grain boundary induced by grain-boundary sliding and migration. The liquid particles on the grain boundary seemed not to impede extensive grain-boundary sliding. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.
Scientific journal, English - Effect of dispersed liquid B2O3 particles on high-temperature mechanical behavior of copper bicrystals
H Miura; T Sakai; H Tamura; G Gottstein
ACTA MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 47, 3, 757-768, Feb. 1999, Orientation controlled Cu bicrystals with dispersed B2O3 particles, where B2O3 behaves liquid like at high temperature, were tensile tested at elevated temperatures. The fracture strain tended to decrease with increasing temperature and misorientation angle, and with decreasing strain rate. At lower temperatures where B2O3 behaves like a solid. the occurrence of grain-boundary fracture was understood by the difference of the time constant for saturated grain-boundary sliding to provide stress concentration sites to promote voids and cracks. Furthermore, at higher temperatures where B2O3 behaves liquid-like, the occurrence of grain-boundary fracture was explained by the loss of grain-boundary strength due to the increasing density of the grain-boundary area fraction of liquid particles and/or formation of liquid film at the grain boundary induced by grain-boundary sliding and migration. The liquid particles on the grain boundary seemed not to impede extensive grain-boundary sliding. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.
Scientific journal, English - Effect of Cold Pre-Rolling on Superplasticity of Nonrecrystallized 7075 Al Alloy,
X.Yang; H.MIuna; T.Sakai
Materials Science Forum, 304-306, 103-108, 1999
Scientific journal, English - Dynamic Recrystallization of Copper Polycrystals with Different Purities, (共著)
W. Gao; A. Belyakov; H. Miura; T. Sakai
Materials Science and Engineering, A265, 233-239, 1999
Scientific journal, English - Grain Refinement under Multiple Warm Deformation in 304 Type Austenitie Stainless Steel, (共著)
A. Belyakov; T. Sakai; H. Miura; R. Kaibyshev
ISIJ International, 39, 592-599, 1999
Scientific journal, English - High Temperature Deformation of Copper Bicrystals Containing Liquid B2O3 Particles, (共著)
H. Miura; T. Otsuka; T. Sakai; S. Onaka
Scripta Materialia, 40, 33-38, 1999
Scientific journal, English - Temperature Dependence of Mechanical Behavior of Copper Bicrystals with Dispersed B2O3 Particles, (共著)
H. Miura; T. Sakai; H. Tamura; G. Gottstein
Materials Science Forum, 294-296, 661-664, 1999
Scientific journal, English - Effect of Cold Pre-Rolling on Superplasticity of Nonrecrystallized 7075 Al Alloy
X. Yang; H. Miura; T. Sakai
Materials science Forum, 304-306, 103-108, 1999
Scientific journal, English - Dynamic Evolution of Fire Groined Structure and Super-plasticity in an unrecrystallized 7075 Aluminum Alloy
楊 続曜; 三浦博己; 酒井 拓
Journal of Japan Institute of Light Metals, 48, 383-388, 1999
Scientific journal, English - 粒界上液体粒子のせん断量による粒界すべりの測定
三浦博己; 酒井 拓; 大塚智弘; 尾中 晋; 門前亮一
日本金属学会講演概要集（第124回春季大会）, 428, 1999
Japanese - 銅双結晶の高温粒界破壊に及ぼす粒界上分散SiO_2_粒子の半径の影響
加藤琢也; 三浦博己; 酒井 拓
日本金属学会講演概要集（第124回春季大会）, 428, 1999
Japanese - SiO_2_，分散粒子を含む銅単結晶の疲労
小谷賢吾; 三浦博己; 酒井 拓
日本金属学会講演概要集（第124回春季大会）, 416, 1999
Japanese - 動的再結晶粒生成過程の計算機シミュレーション
高維林; 酒井 拓; 三浦博己
日本金属学会講演概要集（第124回春季大会）, 431, 1999
Japanese - 動的再結晶のモデリングと粒径分布
高維林; 酒井 拓; 三浦博己
日本金属学会講演概要集（第124回春季大会）, 431, 1999
Japanese - Structure Evolution in 304 Type-Austenite Stainless Steel under Multiple Deformation at 0.5Tm
A. Belyakov; H. Miura; T. Sakai
日本金属学会講演概要集（第124回春季大会）, 431, 1999
English - Cu-15%Cr複相合金の高温変形
高井 裕; 三浦博己; 酒井 拓; 鈴木洋夫
日本金属学会講演概要集（第124回春季大会）, 430, 1999
Japanese - Cu-Al2O3合金の高温変形に及ぼす動的再結晶の影響．
長谷川淳一; 三浦博己; 酒井 拓
日本金属学会講演概要集（第124回春季大会）, 430, 1999
Japanese - 再結晶現象の拡大とその再定義，「再結晶・集合組織とその組織制御への応用」
酒井 拓
日本鉄鋼協会, 2-7, 1999
Japanese - 動的再結晶とその後の静的再結晶，「再結晶・集合組織とその組織制御への応用」
酒井 拓
日本鉄鋼協会, 106-115, 1999
Japanese - 7075AL合金における動的連続再結晶と超塑性発現に関する研究
酒井 拓; 楊続躍; 三浦博己
平成10年度科学研究費補助金（特定領域研究）研究成果報告書「超塑性の新しい展開」(08242102)(代表：佐久間健人),(分担), 142-143, 1999
Japanese - Static Recrystallization of Polycrystalline Copper after Warm and Hot Deformation,
A. M. Wusatouska-Sarnek; H. Miura; T. Sakai
Recrystallization and Related Phenomena（ReX '99）， JIMIS-10, eds. T. Sakai and H. G. Suzuki, JIM,, 149-154, 1999
English - Static Recrystallization of Cold-Rolled Copper Single Crystals with Dispersed SiO2 Particles,
H. Miura; T. Sakai; J. Verhasselt; G. Gottstein
Recrystallization and Related Phenomena（ReX '99），JIMIS-10, eds. T. Sakai and H. G. Suzuki, JIM, 173-178, 1999
English - Dynamic Recrystallization under Warm and Hot Deformation of a 304 Stainless Steel
A. Belyakov; T. Sakai; H. Miura; R. Kaibyshev
Recrystallization and Related Phenomena（ReX '99 ，JIMIS-10, eds. T. Sakai and H. G. Suzuki, JIM, 247-252, 1999
English - On Occurrence of Dynamic Recrystallization in 7475 Aluminum Alloy
R. Kaibyshev; O. Sitdikov; A. Goloborod'ko; A. Belyakov; T. Sakai
Recrystallization and Related Phenomena（ReX '99） ，JIMIS-10, eds. T. Sakai and H. G. Suzuki, JIM, 265-270, 1999
English - Detection of Phase Transformation of Fe Precipitates in Cu-Fe Alloys by Means of Magnetic Measurement
A. M; Wusatouska-Sarnek; Y. Watanabe; T. Sakai; H. Miura
Proceedings of the 2nd Magneto-Electronics International Symposium, Nagano, Shinshu University, 259-262, 1999
English - Coherency Constrains and Martensite Transformation of Iron Particles Embedded in Cu-Fe Matrix
A. M. Wusatouska-Sarnek; H. Miura; T. Sakai
Solid Solid Phase Transformation '99（JIMIC-3），eds., M. Koiwa et alJapan Inst. Metals,（Kyoto）, 903-906, 1999
English - Grain Refinement in a 304 Type Stainless Steel caused by Multiple Warm Deformation（Invited）
A. Belyakov; T. Sakai; H.Miura
International session on"Micro- structural Development and Mechanical Properties for High Strength Steels, Camp-ISIJ, 12, 1332, 1999
English - 冷延Cu-SiO_2_単結晶の静的再結晶挙動
三浦博己; 酒井 拓
日本金属学会講演概要集（第125回秋期大会）, 350, 1999
Japanese - Substructures and Internal Stresses Developed in Continuous Dynamic Recrystallization Structures
A. Belyakov; T. Sakai; H.Miura
日本金属学会講演概要集（第125回秋期大会）, 395, 1999
English - 動的再結晶に伴う応力-ひずみ曲線のシュミレーション
高 維林; 酒井 拓; 三浦博己
日本金属学会講演概要集（第125回秋期大会）, 462, 1999
Japanese - 未再結晶7075Al合金の超塑性変形下の微細粒形成過程-EBSP解析による調査
揚 続躍; 三浦博己; 酒井 拓
日本金属学会講演概要集（第125回秋期大会）, 474, 1999
Japanese - Effect of Deformation Temperature on Static Recrystallization of Copper
A. Wusatouska-Sarnek; H. Miura; T. Sakai
日本金属学会講演概要集（第125回秋季大会）, 549, 1999
English - 動的再結晶による微細粒組織の生成と制御（招待）
酒井 拓
日本金属学会「材料集合組織」研究会資料, 29-32, 1999
Japanese - SiO_2_分散粒子によるCu[001]（110）組織の破壊
三浦博己; 酒井 拓
日本金属学会「材料集合組織」研究会資料, 37-38, 1999
Japanese - 第4回再結晶と関連現象に関する国際会議（Recrystallization '99）-JIMIS10開催報告
酒井 拓
まてりあ（日本金属学会会報）, 38, 12, 993-994, 1999
Japanese - Crystallogeometrical approach to stacking-fault analysis in ordered alloys
SV Dmitriev; AM Wusatowska-Sarnek; MD Starostenkov; AN Belyakov; T Shigenari; T Sakai
ACTA CRYSTALLOGRAPHICA SECTION A, MUNKSGAARD INT PUBL LTD, 54, 430-437, Jul. 1998, Stacking faults (SFs) and antiphase boundaries (APBs) in an n-dimensional ordered alloy with arbitrary primitive cell are analysed from the crystallogeometrical standpoint. The general definition of a SF is given based on the concept of the boundary displacement lattice. The method of enumeration of all possible SFs of a given orientation is proposed. Finally, the energy of an unrelaxed SF is written in terms of the pair-potential functions. The proposed method may be implied as an efficient way of energy estimation and structural analysis of SFs.
Scientific journal, English - New Grain Formation during Warm Deformation of Ferritic Stainless Steel. (共著)
Metallurgical and Materials Trarsactions, 29A, 161-167, 1998
Scientific journal, English - Dynamic recrystallization under warm deformation of polycrystalline copper
A Belyakov; H Miura; T Sakai
ISIJ INTERNATIONAL, IRON STEEL INST JAPAN KEIDANREN KAIKAN, 38, 6, 595-601, 1998, Structural changes taking place under warm deformation of pure copper were studied in compression at temperatures ranging from 473 to 673 K (0.35 to 0.50 T-m) under strain rates of 10(-3)-10(-1) s(-1). Dynamic recrystallization (DRX) takes place fully or partly at temperatures higher than 523 K, while no fine grains are evolved in the pan-caked original grains with serrated boundaries even after high strains at 473 K. The new grains are evolved by bulging mechanism associated with local migration of the original grain boundaries and the evolution of twins and dislocation boundaries. The relationship of peak flow stress to the new grain size evolved under warm deformation can be expressed by a power law function with a grain size exponent of about -0.35, which is different from that for DRX taking place under hot deformation (i.e. -0.75). The correlation between the mechanisms of plastic deformation and the structural evolution, such as dislocation densities, cell sizes, and DRX grain sizes, and the mechanisms of low and high temperature DRX are discussed in combination with the analysis of deformation behaviour at moderate temperatures.
Scientific journal, English - Superplastic Deformation of Boron Doped Fe-18at % Si(共著)
W.-Y. Kim; S. Hanada; T. Sakai
Materials Science and Engineering, A238, 78-86, 1998
Scientific journal, English - Martensitie Transformation of γ-Fe Particles during Compression of Cu-Fe Single Crystals in Conection with Coherency Loss. (共著)
A. M. Wusatouska-Sarnek; H. Miur; T. Sakai
Scripta Materilia, 39, 1457-1461, 1998
Scientific journal, English - Effect of Volume Fraction of Dispersed SiO2 Particlos on Intermediate-Temperature Embrittlenment in Cu-SiO2 Polycrystals(共著)
H. Miura; T. Sakai; G. Gottstein
J. Materials Research, 13, 3100-3105, 1998
Scientific journal, English - Strain Induced Grain Evolution of Polycrystalline Copper under Warm Deformation(共著)
A. Belyakov; W. Gao; H. Miura; T. Sakai
Metallurgical and Meterials Transactions, 29A, 2957-2965, 1998
Scientific journal, English - Dynamic Recrystallization under Warm Deformation of a 304 Type Stainless Steel, (共著)
A. Belyakov; H. Miura; T. Sakai
Materials Science and Engineering, 29A, 139-147, 1998
Scientific journal, English - 分散強化Cu-SiO_2_合金双結晶の高温延性に及ぼす粒界方位差とガス雰囲気の影響
三浦博己; 田村 久; 酒井 拓
日本機械学会論文集, The Japan Society of Mechanical Engineers, 64A, 624, 2121-2126, 1998, Orientation-controlled Cu bicrystals with disperesed SiO2 particles were tensile tested at various temperatures in vacuum and Ar-gas atmospheres. Two kinds of bicrystals having [001] twist 12°and 30°grain boundaries were employed. 30°bicrystal specimens fractured intergranularly at around the intermediate-temperature range, although 12°ones fractured transgranularly at all the temperatures. The elongation to fracture was smaller when deformed in Ar atmosphere than in vacuum almost at all the temperatures irrespective of the bicrystal specimens. The above results could be reasonably understood by considering the difference of the mean grain-boundary strength, the inherent grain-boundary strength, and the effect of gas atmosphere which would be responsible for the acceleration of void formation and growth.
Japanese - 再結晶に関する最近の研究動向
酒井 拓
Overview講演（招待），日本金属学会講演概要集（第122回大会）, 138, 1998
Japanese - Fe-7%Cr合金の動的相動態に伴うフェライト粒組織の形成
佐々木一浩; 三浦博己; 酒井 拓
日本金属学会講演概要集（第122回大会）, 251, 1998
Japanese - Cu-Al_2_O_3_複合材の高温変形と動的再結晶
長谷川淳一; 三浦博己; 酒井 拓
日本金属学会講演概要集（第122回大会）, 250, 1998
Japanese - 鉄鋼の高速変形
酒井 拓
日本鉄鋼協会「自動車用材料の高速変形」研究会資料, 1998
Japanese - 温間強変形に伴う新微細粒組織の形成過程
A. Belyakov; 三浦博己; 酒井 拓
日本鉄鋼協会「再結晶集合組織」研究会資料, 1998
Japanese - 液体B_2_O_3_粒子を分散させたCu双結晶の高温変形と破壊
三浦博己; 田村 久; 酒井 拓
日本金属学会「結晶性材料の高温強度」研究会資料, 1998
Japanese - 未再結晶Al合金における微細粒の動的形成と超塑性発現
楊続躍; 三浦博己; 酒井 拓
日本金属学会「結晶性材料の高温強度」研究会資料, 1998
Japanese - Strain Induced Grain Refinement and Dynamic Recrystallization in Copper under Warm Deformation
A. Belyakov; H. Miura; T. Sakai
日本金属学会「結晶性材料の高温強度」研究会資料, 1998
English - Grain Refinement in 304 Type Austenite Stainless Steel under Multiple Warm Deformation
A. Belyakov; H. Miura; T. Sakai
日本金属学会講演概要集（微細組織の評価と力学特性シンポジュウム）（第123回秋季大会）, 82, 1998
English - 未再結晶7075AI合金の微細粒と超塑性の同時発現における粒界すべりの役割
楊続躍; 三浦博己; 酒井 拓
日本金属学会講演概要集（第123回秋季大会）, 358, 1998
Japanese - Cu-Al_2_O_3_合金の動的再結晶に及ぼすAl_2_O_3_の影響
長谷川 淳一; 三浦博己; 酒井 拓
日本金属学会講演概要集（第123回秋季大会）, 229, 1998
Japanese - 液体B_2_O_3_粒子を含むCu双結晶の粒界破壊
三浦博己; 田村 久; 酒井 拓
日本金属学会講演概要集（第123回秋季大会）, 527, 1998
Japanese - Coherency Loss in Fe Particles Embeded in Cu Matrix during Deformation
A. Wusatouska-Sarnek; H. Miura; T. Sakai
日本金属学会講演概要集（第123回秋季大会）, 264, 1998
English - Enhanced Grain-Boundary fracture of Cu Bicrystals Induced by Dispersed Liquid B_2_O_3_Particles
H. Miura; H. Tamura; T. Sakai
Inter. Symp. on Solid Junction, Abstract P.12, 1998
English - Grain-Boundary Embrittlement in Cu Bicrystals by Bi Segregation,
R. Monzen; T. Kuze; H. Miura
Inter. Symp. on Solid Junction, Abstract P.14, 1998
English - 7075AL合金における動的連続再結晶と超塑性
楊続躍; 三浦博己; 酒井 拓
平成10年度科研費特定領域研究成果報告会 重点研究273「超塑性の新しい展開」研究報告会, 83, 1998
Japanese - Recrysktallization and Related Phenomena
T. Sakai; K. Tsuzaki
ISIJ International（Special Issue）, eds. T. Sakai and K. Tsuzaki, 38, 509, 1998
English - Intermodiate-Temperature Embrittlement of Cu Bicrystals with Dispersed Fe Particles(共著)
Interface Science, 4, 329-338, 1997
Scientific journal, English - Dynamic Evolution of Fine Grained Structure and Superplasticity of 7075 Aluminum Alloy. (共著)
Materials Science and Engineering, A234-236, 857-860, 1997
Scientific journal, English - Effect of cold pre-rolling on superplasticity of warm-worked 7075 aluminum alloy
XY Yang; H Miura; T Sakai
JOURNAL OF THE JAPAN INSTITUTE OF METALS, JAPAN INST METALS, 60, 8, 727-733, Aug. 1996, Superplasticity of the prior cold- and warm-morked 7075 aluminum alloy, especially the effect of prior cold-rolling on it, was studied in tension at 798 K and at various strain rates from 10(-5)s(-1) to 10(-1) s(-1). Continuous dynamic recrystallization takes place during hot deformation, leading to the evolution of fine grained structure. With increasing prior cold-rolling reduction, new finer grains are evolved faster in the unrecrystallzed matrices and their following coarsening is retarded up to higher strains. These are caused by the pancaking of initial grains developed by cold-rolling, which leads to the decrease in the shortest grain diameter. The strain rate dependence of flow stress and total elongation to fracture is affected sensitively by such a grain refinement, which improves the superplastic characteristics in the medium region of strain rate. It is concluded that superplasticity takes place in 7075 aluminum alloy cold- and warm-worked under appropriate conditions and can be controlled mainly by grain boundary sliding.
Scientific journal, Japanese - Effect of temperature and strain rate on superplasticity of warm-worked 7075 aluminum alloy
XY Yang; H Miura; T Sakai
JOURNAL OF THE JAPAN INSTITUTE OF METALS, JAPAN INST METALS, 60, 7, 625-632, Jul. 1996, Hot deformation of prior warm-worked 7075 aluminum alloy was studied by means of 2-step tensile tests at temperatures ranging from 673 to 798 K and at various strain rates from 10(-5) s(-1) to 10(-1) s(-1). Deformation behavior and structural development change at a critical temperature T-c around 730 K. In the region below T-c, a power law relationship with n similar or equal to 3.3 is established between strain rate and flow stress, which suggests the deformation is controlled by the dragging motion of dislocations. In the region over T-c, the strain rate dependence of flow stress changes clearly in three regions of strain rate, epsilon over dot. Typical superplasticity taking place in the medium region of epsilon over dot results from the evolution of fine gained structure based on continuous dynamic recrystallization. It is concluded that hot deformation of the warm-worked 7075 aluminum alloy is affected by the changes in microstructure with temperature and straining, and can be controlled by dislocation motion in grains in the region of high epsilon over dot or by grain boundary sliding in the regions of medium and low epsilon over dot.
Scientific journal, Japanese - Strain Rate Effect on Intermediate Temperature Embrittlement of Cu-SiO2 Bicryotals with [001] Twist Boundaries(共著)
Philosophical Magazine A, 73, 4, 871-882, 1996
Scientific journal, English - 温間変形した7075アルミニウム合金の超塑性に及ぼす冷間予圧延の影響.(共著)
Journal of Japan Institute of Metals, 60, 8, 727-733, 1996
Scientific journal, Japanese - DYNAMIC RECRYSTALLIZATION MICROSTRUCTURES UNDER HOT-WORKING CONDITIONS
T SAKAI
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY, ELSEVIER SCIENCE SA LAUSANNE, 53, 1-2, 349-361, Aug. 1995, The characteristics of high temperature flow curves and evolution of new grain structures under conditions of dynamic recrystallization (DRX) are reviewed, together with the associated development of dislocation substructures. It is shown that the type of DRX taking place depends on the relative grain size D-o/D-s, where D-o and D-s are the initial and stable dynamic grain sizes, and also on the nature of dispersion particles. These can be attributed to that dynamic nucleation occurs mainly at or near existing grain boundaries, and dynamic growth is controlled by not only the temperature corrected strain rate Z, but also dispersion particles. The work softening accompanied with DRX results from a change in the substructural nature from homogeneous to heterogeneous. The dislocation substructures under full DRX are classified into the three categories: (i) DRX nuclei, (ii) growing DRX grains containing a dislocation density gradient, and (iii) large DRX grains with fairly homogeneous substructure. Finally, the metadynamic or post-dynamic restoration processes taking place in the DRX matrices are reviewed. The static softening-annealing time curve observed after DRX consists of three distinct stages with the respective inflection plateaus, followed by incomplete softening (stage 1, 2 and 3). The rate of grain growth at stage 3 is much lower than that of normal grain growth. These can be caused by the stable existence of growing DRX grains having many-sided irregular shapes as well as high density dislocations.
Scientific journal, English - EFFECT OF PRIOR WARM-DEFORMATION ON MICROSTRUCTURE EVOLUTION IN SUPERPLASTIC-7075 ALUMINUM-ALLOY
XY YANG; H MIURA; T SAKAI
JOURNAL OF THE JAPAN INSTITUTE OF METALS, JAPAN INST METALS, 59, 6, 612-619, Jun. 1995, The effect of prior warm-deformation on microstructure development in superplastic 7075 aluminum alloy was studied by means of 2-step tensile testing and metallographic observation. In the case of warm-deformation to over a critical strain epsilon(pc) at intermediate temperatures from 573 to 623 K, the microstructures developed exist quite stably for a long period of time (e.g. 10(6) s) compared with those cold-rolled (e.g. less than few seconds) or warm-deformed to below epsilon(pc), then leading to the appearance of superplasticity during deformation at high temperatures. Mew dislocations evolved by warm-deformation are pinned by eta-phase particles which are reprecipitated during their coarsening or dissolving, and so the initial inhomogeneous microstructures change to the ones distributed homogeneously all over accompanied with dynamic recovery, when straining over epsilon(pc). The apparent activation energy for recrystallization decreases with its progress and finally approaches that for the self-diffusion of aluminum atoms. It is concluded that high density dislocations and fine particles reprecipitated on them can cc-exist stably through their strong interaction and than static recovery as well. as recrystallization taking place in such substructures can be retarded extensively at high temperatures.
Scientific journal, Japanese - EFFECT OF PURITY ON STATIC GRAIN-GROWTH IN DYNAMICALLY RECRYSTALLIZED COPPER
T SAKAI; Z XU
JOURNAL OF THE JAPAN INSTITUTE OF METALS, JAPAN INST METALS, 59, 2, 125-132, Feb. 1995, Effect of purity on static softening and grain growth taking place after dynamic recrystallization (DRX) was studied by means of interrupted compression tests and metallographic observations for the three kinds of polycrystalline coppers, the purities of which were 99.9(3N), 99.99(4N) and 99.9999(6N) mass%. The fractional softening-holding time (X-t) curves after dynamic recovery consist of two stages, followed by complete softening. In contrast, the softening curves for DRX matrices consist of three distinct stages accompanied with three plateaus, followed by incomplete softening (stage I, II. and III). The X-t curves for DRX 3N and 4NCu are almost the same, but clearly different from that for 6NCu. The static softening for DRX 6NCu takes place one order of magnitude faster than that for 3N or 4NCu and finally approach X=1 after a long period of annealing time in stage III. The average rate of grain growth in stage III is always smaller than that for normal grain growth, although both the rates are controlled by grain boundary diffusion irrespective of purity of copper. This results from the stable existence of metadynamically recovered grains which have many-sided irregular shapes as well as high density dislocations. As these grains are metastable in thermodynamics, however, DRX matrices only for 6NCu finally replace fully recrystallized ones, followed by the occurrence of normal grain growth.
Scientific journal, English - ADVANCES IN DYNAMIC RECRYSTALLIZATION AND ITS RELATED PHENOMENA
T SAKAI
TETSU TO HAGANE-JOURNAL OF THE IRON AND STEEL INSTITUTE OF JAPAN, IRON STEEL INST JAPAN KEIDANREN KAIKAN, 81, 1, 1-9, Jan. 1995
Scientific journal, Japanese - EFFECT OF STRAIN-RATE ON INTERMEDIATE-TEMPERATURE EMBRITTLEMENT OF CU-SIO2 BICRYSTALS WITH [001]9-DEGREES TWIST BOUNDARIES
H MIURA; T SAKAI; N TADA; M KATO; T MORI
SCRIPTA METALLURGICA ET MATERIALIA, PERGAMON-ELSEVIER SCIENCE LTD, 32, 2, 185-190, Jan. 1995
Scientific journal, English - EFFECT OF CARBON CONTENT ON STATIC RESTORATION OF HOT WORKED PLAIN CARBON-STEELS
Z XU; GR ZHANG; T SAKAI
ISIJ INTERNATIONAL, IRON STEEL INST JAPAN KEIDANREN KAIKAN, 35, 2, 210-216, 1995, Effect of carbon content on the static softening taking place in hot deformed austenite was studied by means of interrupted tension and compression tests at a temperature of 1 133 K and at a strain rate of 2x10(-3)s(-1) for plain carbon steels. The softening curve after dynamic recovery (DRV) consists of two stages, followed by complete softening. In contrast, the softening curve after dynamic recrystallization (DRX) consists of three distinct stages accompanied with three plateaus, followed by incomplete softening. These can be controlled by metadynamic recovery (MDRV) and recrystallization (MDRX) in addition to classical static recovery (SRV) and recrystallization (SRX). The static softening faking place after DRX sensitively depends on the volume fractions of DRX nuclei, growing DRX grains and fully work hardened DRX grains. The increasing in the fractions of DRX nuclei and growing DRX grains causes the amount of rapid softening in stage I and incomplete softening in stage III to increase, respectively. The static softening rates in DRV and DRX matrices increase with carbon content because of the increased diffusivity of vacancies, which can promote the operation of static restoration mechanisms, i.e. SRV, SRX, MDRV and MDRX.
Scientific journal, English - Effects of Enviromental Atmospheres on High Temperature Deformation and Fracture of Cu-SiO2(共著)
Scripata Metallurgica et Materiala, 32, 1753-58, 1995
Scientific journal, English - Dynamic Evolution Microstructurps in Superplastic Ni3Al(共著)
Materials Transactions,JIM, 36, 9, 1140-48, 1995
Scientific journal, English - Evolution of Fine Grained Microstructure and Super Plasticity in Warm-Worked 7075 Aluminum Alloy
Journal of Japan Institute of Metals, 59, 12, 1222-29, 1995
Scientific journal, English - EFFECT OF SIO2 VOLUME FRACTION ON HIGH-TEMPERATURE DEFORMATION AND FRACTURE-BEHAVIOR OF CU-SIO2 BICRYSTALS
H MIURA; T SAKAI
JOURNAL OF THE JAPAN INSTITUTE OF METALS, JAPAN INST METALS, 58, 12, 1349-1354, Dec. 1994, High-temperature deformation and fracture behavior of Cu-SiO2 bicrystals with different misorientation angles of 8-degrees and 30-degrees, and SiO2 volume fractions of 0.43% and 1.7% were studied. Though typical intermediate-temperature embrittlement was observed in all the bicrystals, their deformation and fracture behavior depended strongly on the misorientation angle and the volume fraction. The elongation to fracture decreased and the temperature range of low ductility became wider with increase in misorientation angle. The strength increased with increasing volume fraction. Although the elongation to fracture in the 8-degrees bicrystal decreased with increasing SiO2 volume fraction, the elongation to fracture in the 30-degrees bicrystal was almost constant independent of SiO2 volume fraction. These differences in deformation and fracture behavior were reasonably understood by considering the dependence of grain-boundary sliding and stress relaxation on the grain-boundary character.
Scientific journal, English - SOLID-SOLUTION HARDENING AND SOFTENING OF AUSTENITE IN PLAIN CARBON-STEEL
T SAKAI; Z XU; GR ZHANG
TETSU TO HAGANE-JOURNAL OF THE IRON AND STEEL INSTITUTE OF JAPAN, IRON STEEL INST JAPAN KEIDANREN KAIKAN, 80, 7, 557-561, Jul. 1994, Solid solution hardening and softening of austenite, i.e. completely opposite phenomena, have been reported for plain carbon steel. These problems were studied in tension and compression tests for 0.05 to 0.84 mass % carbon steels. The shapes of dynamic recrystallization (DRX) type flow curves are almost independent of carbon content. Peak flow stress as well as steady state flow stress rapidly decrease with increase in carbon content and approach a certain value in high concentration, i.e. solid solution softening takes place in the range of higher strain. On the other hand, flow stresses in the range of initial work hardening rapidly increase and then go to a saturation, i.e. solid solution hardening occurs at lower strains. The solid solution softening for stresses at higher strain can be attributed to the enhanced DRX caused by increased diffusivity of vacancy due to the addition of carbon. In contrast, the solid solution hardening for stresses at lower strain may be caused by the increase of dragging stress for dislocation motion due to carbon atmosphere or excess vacancy.
Scientific journal, Japanese - EFFECT OF GRAIN-BOUNDARY MISORIENTATION ON DYNAMIC RECRYSTALLIZATION OF CU-SI BICRYSTALS
H MIURA; H AOYAMA; T SAKAI
JOURNAL OF THE JAPAN INSTITUTE OF METALS, JAPAN INST METALS, 58, 3, 267-275, Mar. 1994, The effect of grain-boundary character on dynamic recrystallization was studied by means of hot-tensile tests and metallographic observations. For this purpose, Cu-Si alloy bicrystals having several [001] twist boundaries were hot-deformed at a temperature of 1023 K and a strain rate of 4.17 x 10(-4) s-1, followed by H-2 gas quenching. As misorientation angle (grain-boundary energy) increases, dynamic recrystallization took place easier at grain boundary. This grain-boundary dependent characteristic of dynamic recrystallization was closely attributable to the difference in the occurrence of grain-boundary sliding, grain-boundary serration and piling up of dislocations to grain boundary followed by the development of inhomogeneous dislocation substructure nearby grain boundary. Accompanying these results, a new model of dynamic recrystallization, in which dynamic nuclei can be formed by bulging out of part serrated grain-boundary, is proposed.
Scientific journal, Japanese - Effect of Dispersion Particles on Dynamic Recrystallization of Cu-Be Alloys.
Journal of Japan Institute of Metals, 58, 1, 15-22, 1994
Scientific journal, English - Embrittlement of Cu [110] Symmetric Boundaries Induced by Bi Segregation
Journal of Japan Institute of Metals, 58, 5, 477-482, 1994
Scientific journal, English - Embrittlement of [001] Twist Grain Boundary Induced by Bi Segregation(共著)
Appl. Phys. Lett., 65, 6, 705-707, 1994
Scientific journal, English - Ductility and Fracture of Cu Bicrystals with Boundary SiO2 Particles(共著)
Materials Science and Technology, 10, 10, 1044-1049, 1994
Scientific journal, English - DYNAMIC RECRYSTALLIZATION OF A COMMERCIAL CU-BE-CO ALLOY DURING HOT DEFORMATION
T SAKAI; H MIURA; T IWAI; N MURAMATSU
JOURNAL OF THE JAPAN INSTITUTE OF METALS, JAPAN INST METALS, 57, 12, 1390-1396, Dec. 1993, Hot deformation as well as dynamic recrystallization (DRX) of a commercial Cu-Be25(Cu-1.8Be-0.25Co) alloy were studied by means of tensile testing and microstructural observation at the temperature ranging 923 K to 1123 K under strain rates of 10(-5) to 10(-1) s-1. The flow curves showed a sharp yield point phenomenon followed by work softening and steady state flow at higher Z (= epsilon exp (Q/RT)), although they showed normal yielding, work hardening and then steady state flow at lower Z. DRX took place during work softening or hardening and led to an equilibrium or stable grain structure at high strains. The stable structure, which was dependent on T or epsilon, consisted of a mixture of fine grains and comparatively coarse grains with many sided irregular boundaries at higher Z. In contrast, almost equiaxial grains with smooth or straight boundaries were observed at lower Z. A relationship between the steady state flow stress sigma(s) and the stable dynamic grain size D(s) is almost the same as that of Cu at higher Z, but it shifted towards a finer grain side at lower Z. Such different types of DRX are discussed by considering the roles of alloying elements of Be and Co. It is concluded that yielding flow can be controlled by the viscous motion of dislocations which drag the solute atmosphere composed of Be atoms, and on the other hand, steady state flow can be controlled by DRX assisted by the volume diffusion of Cu atoms.
Scientific journal, Japanese - EMBRITTLEMENT OF CU [110] SYMMETRICAL TILT BOUNDARIES INDUCED BY BI SEGREGATION
H MIURA; T YOSHIDA; T SAKAI; M KATO; T MORI
JOURNAL OF THE JAPAN INSTITUTE OF METALS, JAPAN INST METALS, 57, 5, 479-485, May 1993, Cu bicrystals with various [110] symmetric tilt boundaries doped with Bi were tensile tested. Their fracture behavior depended sensitively on the misorientation angle at the boundaries, Bi doping time and aging temperature. A strong correlation between the fracture behavior and grain-boundary energy before the Bi doping has been found: the higher the grain-boundary energy, the easier becomes the brittle fracture at grain boundaries. As the Bi doping time increased, grain-boundary brittle fracture occurred more easily. These phenomena could be explained resonably by considering the boundary-dependent amount of segregation of Bi atoms.
Scientific journal, Japanese - Temperature Dependence of Ductility and Fracture of Cu-SiO2 Bicrystals with [001] Twist Boundaries, (共著)
Acta Metallurgica and Materials, 41, 4, 1207-1213, 1993
Scientific journal, English - Hot Deformation and Mechanism of Austenitie Steels and a Pure Copper.
酒井 拓; 除 洲
電気通信大学紀要, 電気通信大学, 6, 2, 143-156, 1993
Research institution, English - DEVELOPMENT OF DYNAMICALLY RECRYSTALLIZED BANDS IN POLYCRYSTALLINE NICKEL
M OHASHI; T SAKAI; T ENDO
JOURNAL OF THE JAPAN INSTITUTE OF METALS, JAPAN INST METALS, 56, 12, 1401-1407, Dec. 1992, The process of dynamically recrystallized (DRX) band formation which takes place after the stress peak followed by its rapid drop has been studied using hot tensile testing of polycrystalline nickel, with microstructural observations being carried out by optical and transmission electron microscopy. Few DRX grains nucleated at a specimen edge and propagated easily across the cross-section during stress drop, and then developed sidewise along the specimen axis. Such processes took place repeatedly accompanied with serrations in stress at high strains. Microstructures inside DRX band showed dislocation density gradient and more ragged cellular boundaries, compared with homogeneous and recovered ones in zero-DRX region. The critical condition at which the DRX band was formed was t = D (Here t and D are the specimen thickness and the stable DRX grain size, respectively.). These results are interpreted in terms of the stability of plastic flow as well as DRX grain growth.
Scientific journal, Japanese - Kinetics of Recovery and Recrystallization in Dynamically Recrystallized Austenite. (共著)
Materials Transactions, JIM, 32, 2, 1991
Scientific journal, English - Effect of True Strain Rate Control on Hot Compression of a 3% Si Steel.
J. Japan Inst. Metals, 55, 3, 1991
Scientific journal, English - Dislocation Substructures Developed during Dynamic Recrystallization in Polycrystalline Nickel(共著)
Materials Science and Technology, 6, 12, 1990
Scientific journal, English - Recovery and Recrystallization of Polycrystalline Nickel after Hot Working. (共著)
Acta Metallurgica, 36, 7, 1988
Scientific journal, English - Flow Stress and Structural Change during the Transient Dynamic Recrystallization of Nickel. (共著)
Materials Science and Technology, 2, 7, 1986
Scientific journal, English - Hot Compression of Lead at Constant True Strain Rates.
J. Japan Soc. for Technology of Plasticity, 26, 299, 1985
Scientific journal, English - Dynamic Recrystallization : Mechanical and Microstructural Consideration(共著)
Acta Metallurgica, 32, 2, 1984
Scientific journal, English - Dynamic Recrystallization during the Transient Deformation of a Vanadium Microalloyed Steel. (共著)
Acta Metallurgica, 31, 4, 1983
Scientific journal, English - The Effect of Temperature, Strain Rate, and Carbon Content on Hot Deformation of Carbon Steels. (共著)
Tetsu-to-Hagane, 67, 11, 1981
Scientific journal, English - Hot Deformation of Austenite in a Plain Carbon Steel. (共著)
Trans. Iron Steel Inst. of Japan, 17, 12, 1977
Scientific journal, English
MISC
Books and other publications
- 塑性加工便覧
酒井 拓
Japanese, Joint work, 鉄鋼の変形抵抗, コロナ社, 2006 - マグネシウム合金の高温加工と再結晶（招待）
酒井拓
Japanese, Editor, 「マグネシウム合金の製造と加工技術の最先端」, 日本金属学会, 2005 - Processing and Manufacturing of Advanced Materials (THERMEC'2003), eds. T. Chandra, J. M. Torralba and T. Sakai
T. Chandra; J. M. Torralba; T. Sakai
English, Materials Science Forum,, 2003 - 改訂6版金属便覧（分担): 加工・再結晶組織
酒井 拓
Japanese, Joint work, 日本金属学会，（丸善）, 2000 - Modeling of the New Grain Development during Dynamic Recrystallization
W. Gao; T. Sakai; H. Miura
English, Recrystallization and Relateol Phenomena(Rex '99), JIMIS-10, eds. T. Sakai and H. G. Suzuki, JIM, 1999 - 再結晶・集合組織とその組織制御への応用 (編著)
酒井 拓
Japanese, Editor, 日本鉄鋼協会, 1999 - Recrystallization and Related Phenomena（ReX '99）
T. Sakai; H. G. Suzuki
English, Editor, eds.T.Sakai and H.G.Suzuki, The Japan Institute of Metals, 1999 - Rocrystallization and Related Phenomena(ReX'99), (共編著)
English, eds. T. Sakai and H. G. Suzuki, Japan Inotitute of Metals, 1998 - Hot Working and Recrystallization in Steels and Other Metals.
English, Physical Simulation of Casting, Hot Working and Welding, ISIJ, 1997 - Recovery, Recrystallizatior and Grain Growth in Dynamically Recrystallized Materials.
English, Recrystallization and Related Phenomena(Rex'96), 1997 - New Grain Formation during Warm Deformation of Materials with High and Low SFE(共著)
English, Thermomechanical Processing of Steels and Other Materials(THERMEC'97), TMS,, 1997 - Thermomechanical Processing of Steels and Other Materials(THERMEC'97)
T. Chardra; T. Sakai
English, Editor, eds. T. Chandra and T. Sakai, TMS, 1997 - Physical Simulation of Casting, Hot Working and Welding, ISIJ
H.G.Suzuki; T.Sakai; F. Matsda
English, Editor, Iron and Steel of Japan (ISIJ), 1997 - Microstructural Development during Dyname Recrytallization of Bicryotals and Polycrystalline Materials(共著)
English, Hot Workability of Steels and Light Alloys-Composites, 1996 - A Model of Nanocrystalline Grain Boundary Formation during Severe Cold Deformation of a High SFE material.(共著)
English, Interface science and Materials Interconnection (JIMIS8), Japan Inst. of Metals, 1996 - Effect of Distribution of Grain-Boundary Particles on Intermediate Temperature Embrittlement of Cu-SiO2 Bicrystals(共著)
English, Strength of Materials (ICSMA10), Japan Institute of Metals, 1994 - Yield Point Phenomenon and Dynamic Recrystallization of Cu-Be Alloy during Hot Deformation(共著)
English, Strength of Materials (ICSMA10), Japan Institute of Metals, 1994 - Fine-Grained Structure Evolution and Superplasticity in Warm-Worked 7075 Aluminum Alloy(共著)
English, Strength of Materials (ICSMA10), Japan Institute of Metals, 1994 - Intermediate Temperature Embrittlement of Cu-SiO2 Bicrystals with [001] Twist Boundaries (共著)
English, Aspects of High Temperature Deformation and Fracture in CrystallineMaterials (JIMIS-7), 1993 - Changes of Flow Stress and Microstructure during Hot Deformation of 7075 Aluminum Alloy (共著)
English, Aspects of High Temperature Deformation and Fracture in Crystalline Materials (JIMIS-7), 1993
Lectures, oral presentations, etc.
- 大ひずみ加工マグネシウム合金の超塑性変形
酒井拓; 三浦博己; 邢劼; 楊続躍
Oral presentation, Japanese, 日本金属学会平成19年度高温材料設計研究会資料,日本金属学会平成19年度高温材料設計研究会
Aug. 2008 - 銅合金の大ひずみ加工とその後の焼きなまし特性
酒井拓
Oral presentation, Japanese, 日本ガイシ特別セミナー資料,日本ガイシ特別セミナー
2008 - 大ひずみ加工誘起による結晶粒微細化プロセスと機構
酒井拓; 三浦博己
Oral presentation, Japanese, 材料とプロセス,材料とプロセス
2008 - アルミニュウム合金の恒温多軸鍛造に伴う微細粒組織の生成
濱; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会第142回春季講演大会講演概要,日本金属学会第142回春季講演大会
2008 - オーステナイト系ステンレス鋼の極低温強ひずみ加工による超微細粒組織
中尾佳史; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会第142回春季講演大会講演概要,日本金属学会第142回春季講演大会
2008 - 加工誘起新粒形成機構と温度の影響
酒井拓; 三浦博己
Oral presentation, Japanese, 日本鉄鋼協会超強加工研究会資料,日本鉄鋼協会超強加工研究会
Nov. 2007 - 銅の加工誘起微細粒生成に及ぼす加工温度の影響
酒井拓
Oral presentation, Japanese, 科学研究費特定研究会資料
Oct. 2007 - マグネシウム合金の動的再結晶と加工特性
酒井拓
Oral presentation, Japanese, マグネシウム鍛造部材技術開発プロジェクト(経済産業省素形材センター)研究会資料,マグネシウム鍛造部材技術開発プロジェクト(経済産業省素形材センター)研究会
Sep. 2007 - 大ひずみ加工後に働く焼なまし諸特性
酒井拓
Oral presentation, Japanese, 科学研究費特定研究会資料,科学研究費特定研究会
May 2007 - アルミニウム合金の高温変形と超塑性
酒井拓
Oral presentation, Japanese, 日本軽金属蒲原工場技術センター講演会資料,日本軽金属蒲原工場技術センター講演会
Mar. 2007 - 分散強化型Ni-Fe合金の温間強ひずみ加工と結晶粒微細化
上野太郎; 酒井拓; 吉永直樹; 藤田展弘
Oral presentation, Japanese, 材料とプロセス
2007 - 銅の冷間，高温加工中と加工後の連続・不連続再結晶
酒井拓
Keynote oral presentation, Japanese, 第46回銅及び銅合金技術研究会講演大会, 銅と銅合金, 46 (2007), 1-6., Domestic conference
2007 - 大ひずみ加工誘起微細粒マグネシウム合金の力学特性，巨大ひずみ加工材料の特異なメカニクスのシンポジウム
酒井拓; 邢劼; 楊続躍; 三浦博己
Oral presentation, Japanese, 日本金属学会第140回春季講演大会講演概要，,日本金属学会第140回春季講演大会
2007 - Temperature Effect on Microstructure Evolution in 2219 Aluminum Alloy during ECAP
I. Mazurina; H. Miura; T. Sakai
Oral presentation, English, 日本金属学会第140回春季講演大会講演概要,日本金属学会第140回春季講演大会
2007 - 冷間加工マグネシウム合金AZ31の回復と再結晶
岡部泰昌; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会第140回春季講演大会講演概要,日本金属学会第140回春季講演大会
2007 - 不連続再結晶のメカニズム
三浦博己; 最川亮; 酒井拓
Oral presentation, Japanese, 日本金属学会第140回春季講演大会講演概要,日本金属学会第140回春季講演大会
2007 - Cu-Zn合金ナノ結晶粒バルク材の再結晶挙動
中尾佳史; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会第140回春季講演大会講演概要,日本金属学会第140回春季講演大会
2007 - 強ひずみ加工中のCu双結晶粒界での優先的な微細粒生成
吉田康浩; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会第140回春季講演大会講演概要,日本金属学会第140回春季講演大会
2007 - マグネシウム単結晶の高温変形挙動とその結晶方位およびひずみ速度依存性
三浦博己; 楊続躍; 酒井拓; 渡辺吉見; 三浦誠司
Oral presentation, Japanese, 軽金属学会大112回春期大会講演概要集,軽金属学会大112回春期大会
2007 - マグネシウム単結晶の高温変形中の再結晶発現組織形成
三浦博己; 楊続躍; 酒井 拓
Oral presentation, Japanese, 日本金属学会「結晶方位と組織の制御」第2回研究会資料集，(2007), 岐阜,日本金属学会「結晶方位と組織の制御」第2回研究会
2007 - 銅および銅合金の結晶粒組織制御技術と機構
酒井拓
Oral presentation, Japanese, 日立電線研究所特別セミナー資料,日立電線研究所特別セミナー
2007 - マグネシウム合金AZ31の大ひずみ加工による組織制御と機械的特性
酒井拓; 邢劼; 楊続躍; 三浦博己
Keynote oral presentation, Japanese, 日本金属学会第142回秋期講演大会, 日本金属学会第142回秋期講演大会講演概要, Domestic conference
2007 - Temperature Effect on Strain-Induced Grain Formation in 2219 Aluminum Alloy during ECAP
I. Mazurina; H. Miura; T. Sakai
Oral presentation, Japanese, 日本金属学会第141回秋期講演大会講演概要,日本金属学会第141回秋期講演大会
2007 - お温間多軸鍛造中の粗大分散粒子によるNi-Fe合金の結晶粒超微細化の促進
三浦博己; 上野太郎; 酒井拓; 吉永直樹; 藤田展弘
Oral presentation, Japanese, 材料とプロセス,材料とプロセス
2007 - 金および金合金の強ひずみ加工と機械的性質
谷雨; 板橋一光; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会第142回秋期講演大会講演概要,日本金属学会第142回秋期講演大会
2007 - Cu-Zn合金の極低温圧延と低温焼鈍による結晶粒超微細化
丸岡正治; 三浦博己; 酒井拓; 山崎周一; 山口洋
Oral presentation, Japanese, 日本金属学会第142回秋期講演大会講演概要,日本金属学会第142回秋期講演大会
2007 - マグネシウム単結晶の高温変形挙動のひずみ速度依存性と変形双晶による組織微細化
三浦博己; 塩谷裕司; 楊続躍; 酒井拓
Oral presentation, Japanese, 軽金属学会第113回秋期大会講演概要集,軽金属学会第113回秋期大会
2007 - アルミニウム合金の大ひずみ加工中の大角境界と新粒組織の形成に及ぼす加工温度の影響
酒井拓; イナ・マズリナ; 三浦博己
Oral presentation, Japanese, 軽金属学会第113回秋期大会講演概要集,軽金属学会第113回秋期大会
2007 - Ultrafine Grain Formation during Severe Plastic Defomation (Keynote Invited)A plenary Lecture in the 5th International Conference on Physical and Numerical Simulation of Materials Processing
T.Sakai
Invited oral presentation, English, ICPNS’29007, ICPNS’29007, Zhengzhou, China, International conference
2007 - 変形双晶導入と低温焼鈍により生成される黄銅の超微細再結晶粒組織
三浦博己; 丸岡正治; 酒井拓; 山口洋; 山崎周一
Oral presentation, Japanese, 第47回銅及び銅合金技術研究会講演概要集,第47回銅及び銅合金技術研究会
2007 - 不連続動的再結晶のメカニズム
三浦博己; 酒井拓
Oral presentation, Japanese, 第47回銅及び銅合金技術研究会講演概要集,第47回銅及び銅合金技術研究会
2007 - ナノ結晶粒黄銅の低温焼鈍による微視組織と機械的性質の変化
中尾佳史; 三浦博己; 酒井拓
Oral presentation, Japanese, 第47回銅及び銅合金技術研究会講演概要集,第47回銅及び銅合金技術研究会
2007 - マグネシウム合金の大ひずみ加工と超塑性変形
酒井拓
Invited oral presentation, Japanese, 第19回高性能マグネシウム合金創成加工研究会, 高性能マグネシウム合金創成加工
Nov. 2006 - 日本金属学会平成18年度高温材料設計研究会資料
酒井拓; A. Goloborodko; 三浦博己
Oral presentation, Japanese, 日本金属学会平成18年度高温材料設計研究会資料,日本金属学会平成18年度高温材料設計研究会
Aug. 2006 - 分散銅合金の高温での粒界強度と方位依存性
三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会平成17年度高温材料設計研究会資料,日本金属学会平成17年度高温材料設計研究会
Aug. 2006 - 大ひずみ誘起結晶粒組織展開に及ぼす温度とひずみ速度の影響
酒井拓; A. Goloborodko; 三浦博己
Oral presentation, Japanese, 日本金属学会平成18年度高温材料設計研究会資料,日本金属学会平成18年度高温材料設計研究会
Aug. 2006 - 「大ひずみ加工誘起による超微細粒組織の生成機構並びに特性評価」
酒井拓
Others, Japanese, 科学研究費補助金,科学研究費補助金研究成果報告書
Mar. 2006 - 動的再結晶理解の歴史的展開
酒井拓
Invited oral presentation, Japanese, 第3回超強加工研究会, 日本鉄鋼協会
Feb. 2006 - High Angle Boundary Formation in Dynamically Recovered Material during Severe Plastic Deformation
Taku Sakai
Keynote oral presentation, English, Ultrafine Grained Materials IV, International conference
2006 - マグネシウム合金の加工誘起微細粒かと超塑性特性
酒井拓
Keynote oral presentation, 「マグネシウム合金の新展開－次世代輸送機用部材を目指して」シンポジウム, 日本金属学会, Domestic conference
2006 - 動的再結晶の力学的，組織学的特性と機構
酒井拓
Keynote oral presentation, Japanese, 日本鉄鋼協会討論会「動的再結晶の理解の深まりと工業的応用」, 日本鉄鋼協会, Domestic conference
2006 - Continuous dynamic recrystallization in 7475 Al alloy during transient hot deformation,
A. Goloborodko; H. Miura; T. Sakai
Oral presentation, English, 日本金属学会,日本金属学会(第138回春期講演大会)
2006 - 高温加工マグネシウム合金AZ31の焼きなまし特性に及ぼす加工ひずみの影響
岡部泰昌; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会,日本金属学会（第138回春期講演大会）
2006 - 高温加工マグネシウム合金AZ31の焼きなまし特性に及ぼす加工誘起結晶粒径の影響
西郷翔; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会,日本金属学会（第138回春期講演大会）
2006 - Fe-20%Cr合金の大ひずみ加工と微細粒組織生成に及ぼす加工温度の影響
堀井長彦; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会,日本金属学会（第138回春期講演大会）
2006 - 純Mg単結晶の高温変形挙動に関する研究
塩谷裕司; 三浦博己; 酒井拓; 渡辺義見; 三浦誠司
Oral presentation, Japanese, 日本金属学会,日本金属学会（第138回春期講演大会）
2006 - Cu-Fe双結晶の粒界における動的再結晶の方位依存性
塚脇悠; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会,日本金属学会（第138回春期講演大会）
2006 - 強ひずみ加工Cu-Fe-P合金の疲労特性とその温度依存性
劉剛; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会,日本金属学会（第138回春期講演大会）
2006 - 分散粒子を含むCu粒界の高温変形中の応力集中と強度
三浦博己; 八木和雄; 酒井拓; 戸田裕之
Oral presentation, Japanese, 日本金属学会,日本金属学会（138回春季講演大会）
2006 - Fine-Grained Structure Formation in 7475 Al Alloy during Hot Multidirectional Forging
A. Goloborodko; H. Miura; T. Sakai
Oral presentation, English, 軽金属学会大110回春期大会講演概要集
2006 - 大ひずみ加工マグネシウム合金の焼きなまし特性に及ぼす加工温度の影響
楊続躍; 西郷翔; 三浦博己; 酒井 拓
Oral presentation, Japanese, 軽金属学会大110回春期大会講演概要集,軽金属学会大110回春期大会
2006 - マグネシウム合金AZ31の降温中多軸鍛造に伴う微細粒組織生成と超塑性機構
邢 劼; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 軽金属学会大110回春期大会講演概要集，(2006), .,軽金属学会大110回春期大会
2006 - AZ31,AZ61合金の降温多軸鍛造による結晶粒微細化と機械的性質
三浦博己; 楊続躍; 邢 劼; 酒井拓
Oral presentation, Japanese, 軽金属学会大110回春期大会講演概要集
2006 - アルミニウム合金の変形誘起結晶粒組織の展開に及ぼす変形速度の影響
A. Goloborodko; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会第139回秋季講演大会講演概要，(2006),510.
2006 - 高強度黄銅の微視組織生成過程の観察
すけ川英幸; 三浦博己; 酒井拓; 吉村卓造; 山口洋; 山崎周一
Oral presentation, Japanese, 日本金属学会第139回秋季講演大会講演概要,日本金属学会第139回秋季講演大会
2006 - 結晶粒組織の制御技術と機構－連続／不連続動的再結晶とその後の静的再結晶
酒井 拓
Keynote oral presentation, Japanese, 第46回銅及び銅合金技術研究会, 第46回銅及び銅合金, Domestic conference
2006 - Cu-Be25合金の多軸鍛造処理後の時効硬化特性
村松尚国; 千葉広樹; 玉昌峰; 三浦博己; 酒井拓
Oral presentation, Japanese, 第46回銅及び銅合金技術研究会講演概要集,第46回銅及び銅合金技術研究会
2006 - 黄銅の多軸鍛造による変形双晶発達と結晶粒超微細化
中尾佳史; 三浦博己; 酒井拓
Oral presentation, Japanese, 第46回銅及び銅合金技術研究会講演概要集,第46回銅及び銅合金技術研究会
2006 - 高強度黄銅の製造過程における微細組織の発達
すけ川英幸; 三浦博己; 酒井拓; 吉村卓造; 山口洋; 山崎周一
Oral presentation, Japanese, 第46回銅及び銅合金技術研究会講演概要集,第46回銅及び銅合金技術研究会
2006 - Cu-Zn合金の最終低温焼鈍工程における微視組織と機械的性質の変化
稲生 剛; 酒井拓; 三浦博己; 酒井拓; 山口洋; 山崎周一
Oral presentation, Japanese, 第46回銅及び銅合金技術研究会講演概要集,第46回銅及び銅合金技術研究会
2006 - Cu-Fe-P合金の多軸鍛造法による結晶粒超微細化と疲労挙動
三浦博己; 劉剛,酒井拓
Oral presentation, Japanese, 第46回銅及び銅合金技術研究会講演概要集,第46回銅及び銅合金技術研究会
2006 - 分散強化銅合金の高温での粒界強度と粒界破壊
三浦博己; 八木和雄; 酒井拓
Oral presentation, Japanese, 第46回銅及び銅合金技術研究会講演概要集,第46回銅及び銅合金技術研究会
2006 - 塑性加工に伴う大角境界と微細粒組織の形成機構－連続，不連続再結晶現象
酒井拓
Invited oral presentation, Japanese, 物質・材料研究機構特別セミナー, 物質・材料研究機構
Nov. 2005 - High-Temperature Cyclic Creep and Fracture Behavoir of Cu-SiO2 Bicrystals
H. Miura; Y. Ito; T. Sakai
Invited oral presentation, English, Extended Abstracts of ICF-11, Extended Abstracts of ICF-11, Italy, International conference
Mar. 2005 - 鉄鋼の動的再結晶と組織制御
酒井拓
Invited oral presentation, Japanese, 新日本製鉄鉄鋼研究所セミナー, 新日本製鉄鉄鋼研究所セミナー
Jan. 2005 - 銅合金の粒界近傍の下部組織と動的再結晶の発現
三浦博己; 酒井拓; A. Belyakov; 津崎兼彰
Oral presentation, Japanese, 日本金属学会講演概要集（第136回春期講演大会）,日本金属学会 第136回春期講演大会
2005 - Fine-Grained Structure Formation in 7475 Al Alloy during Hot Severe Forging
A. Goloborodko; O. Sitdikov; H. Miura; T. Sakai
Oral presentation, English, 日本金属学会講演概要集（第136回春期講演大会）,日本金属学会 第136回春期講演大会
2005 - Ultra-Fine Grain Formation in an Aluminum Alloy 2219 during ECAP
I. Mazurina; O. Sitdikov; H. Miura; T. Sakai
Oral presentation, English, 日本金属学会講演概要集（第136回春期講演大会)
2005 - マグネシウム合金AZ31の降温多軸鍛造に伴う微細粒組織生成，
惣田裕司; 邢 劼; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第136回春期講演大会）,日本金属学会（第136回春期講演大会）
2005 - 大ひずみ加工Cu-Ni-Be合金の微細粒組織生成と時効硬化
竹中勝敏; 楊属躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第136回春期講演大会),日本金属学会（第136回春期講演大会)
2005 - マグネシウム合金の高温変形と動的再結晶挙動の粒径依存性
三浦博己; 楊続躍; 邢 劼; 酒井拓
Oral presentation, Japanese, 日本軽金属学会,第108回軽金属春期大会
2005 - 超微細粒マグネシウム合金AZ31の低温超塑性挙動と組織変化
邢 劼; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本軽金属学会,第108回軽金属春期大会
2005 - 軽合金の高温加工と微細粒組織生成
酒井拓
Oral presentation, Japanese, 日本軽金属,日本軽金属（株）技術研究所特別セミナー
2005 - 粒界三重点での優先的な動的再結晶の発現と双晶形成
三浦博己; Sutandyo Andiawarwant; 酒井拓
Oral presentation, Japanese, 日本金属学会,日本金属学会集合組織研究会
2005 - 大ひずみ加工に伴う大角境界の高温加工と新微細粒組織の発達
酒井拓
Oral presentation, Japanese, 日本ガイシ（株）技術研究所特別セミナー,日本ガイシ（株）技術研究所特別セミナー
2005 - Microstructural Evolution in 7475 Al Alloy during Warm Severe Forging
A. Goloborodko; O.Sitdikov; H. Miura; T. Sakai
Oral presentation, English, 日本金属学会,日本金属学会（第137回秋期講演大会, JIM-ISIJ国際共同セッション）
2005 - Microstructural evolution of a 2219 Al Alloy during ECAE at 723K
I. Mazurina; H. Miura; T. Sakai
Oral presentation, English, 日本金属学会,日本金属学会（第137回秋期講演大会)
2005 - 超微細粒マグネシウム合金AZ31の低温超塑性と組織変化
邢 劼; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会,日本金属学会（第137回秋期講演大会）
2005 - マグネシウム合金AZ31の動的再結晶に及ぼす温度と初期粒径の影響
楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会,日本金属学会（第137回秋期講演大会）
2005 - 銅の極低温強ひずみ加工とその後の再結晶挙動
中尾佳史; 酒井拓; 楊続躍; 和田正彦; 三浦博己
Oral presentation, Japanese, 日本金属学会,日本金属学会 第137回秋期講演大会
2005 - Mg多結晶の動的再結晶と破壊挙動
三浦博己; 楊続躍; 酒井拓; 渡辺義見; 三浦誠司
Oral presentation, Japanese, 軽金属学会,第107回軽金属秋季大会
2005 - 超微細粒マグネシウム合金AZ31の低温超塑性に及ぼす異方性の影響
邢 劼; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 軽金属学会,第107回軽金属秋季大会
2005 - 新たな結晶粒微細化法の探求と検討
三浦博己; 酒井拓
Oral presentation, Japanese, 銅及び銅合金技術研究会,第45回銅及び銅合金技術研究会
2005 - 軽合金の動的再結晶と高温加工中の組織制御
酒井拓
Keynote oral presentation, Japanese, 軽金属関西支部軽金属基礎シンポジウム「回復・再結晶の最前線」, 軽金属学会, Domestic conference
Nov. 2004 - Dynamic Recrystallization and Microstructural Control under Cold/Hot Working Conditions
Taku Sakai
Invited oral presentation, English, Special seminar in the Institute of Metals Superplasticity Problems,, Ufa, Russia, Russia, International conference
Sep. 2004 - 整合または非整合析出粒子を含む銅の高温変形挙動
三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会,日本金属学会平成16年高温材料設計研究会資料
Aug. 2004 - Grain Refinement in High Strength Aluminum Alloy during Hot Deformation
A. Goloborodko; H. Miura; T. Sakai
Oral presentation, Japanese, 日本金属学会,日本金属学会平成16年度高温材料設計研究会
Aug. 2004 - Grain Refinement in BCC/FCC Steels during Severe Forging
Taku Sakai
Invited oral presentation, English, Special seminar in Ecole Nationale Superieure des Mines de Saint-Etienne, Saint-Etienne , France, France, International conference
Aug. 2004 - Mg単結晶の高温変形と延性
三浦博己; 楊続躍; 酒井拓; 渡辺義見; 三浦誠司
Oral presentation, Japanese, 日本金属学会,日本金属学会平成17年度高温材料設計研究会
Aug. 2004 - マグネシウム合金AZ31の高温加工後の焼きなまし特性と粒成長
楊続躍; 三浦博己; 酒井 拓
Oral presentation, Japanese, 日本金属学会,日本金属学会平成17年度高温材料設計研究会
Aug. 2004 - Fine-Grained Structure Formation in Al Alloy during Multi-directional Forging
A. Goloborodko; H. Miura; T. Sakai
Oral presentation, English, 日本金属学会,日本金属学会平成17年度高温材料設計研究会
Aug. 2004 - 塑性加工に伴う高角境界の形成と微細粒組織
酒井 拓
Keynote oral presentation, Japanese, 日本金属学会平成17年度高温材料設計研究会, 日本金属学会, Domestic conference
Aug. 2004 - 高強度アウミニウム合金の高温変形中の回復と再結晶
酒井拓
Others, Japanese, 日本軽金属蒲原工場技術センター講演会資料
Mar. 2004 - 金属・合金の動的再結晶と高温加工下組織制御（谷川・ハリス賞受賞講演），
酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第134回春期大会）
2004 - 金属・合金の動的再結晶と高温加工下組織制御（谷川・ハリス賞受賞講演），
酒井拓
Invited oral presentation, Japanese, 日本金属学会講演概要集（第134回春期大会）
2004 - 銅の195Kにおける多軸鍛造による超微細粒組織の生成
小林千紘; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第134回春期大会）
2004 - マグネシウム合金AZ31の動的再結晶に及ぼす温度の影響
真田昌美; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第134回春期大会）
2004 - マグネシウム合金AZ31の温間圧縮変形に伴う双晶形成と動的再結晶
楊続躍; 真田昌美; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第134回春期大会）
2004 - 銅の高温変形微視組織に及ぼすFe析出粒子形態の影響
三浦博己; 塚脇 悠; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第134回春期大会）
2004 - Cu-1.4%Fe-0.6%Cr合金の強ひずみ加工による組織微細化に及ぼす第2相粒子の影響
瀬川泰三; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第134回春期会）
2004 - Microstructural Control Due to Continuous and Discontinuous Dynamic Recrystallization (Invited),
Taku Sakai
Keynote oral presentation, English, ICPNS’2004-Proceedings of the 4th Int’l Conf. on Physical and Numerical Simulation of Materials Processing, (Shanghai, China, 2004): CDrom, ed by J. T. Niu, International conference
2004 - Multidirectional Forging of Austenitic Stainless Steel with Second Phase Particles,
H. Miura; H. Hamaji; T. Sakai
Public symposium, English, 第8回超鉄鋼ワークショップ，新構造の提案と求められる材料技術, 物質材料研究機構
2004 - 高温加工マグネシウム合金AZ31の静的再結晶挙動に及ぼす加工速度の影響
楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会 日本金属学会講演概要集（第135回秋期講演大会）,日本金属学会（第135回秋期講演大会）
2004 - マグネシウム合金AZ31の降温多軸鍛造に伴う微細粒組織生成
惣田裕司; 邢 劼; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会 日本金属学会講演概要集（第135回秋期講演大会）,日本金属学会（第135回秋期講演大会）
2004 - Fine-Grained Structure Formation of 7475 Al Alloy during Severe Hot Deformation
A. Goloborodko; O. Sitdikov; H. Miura; T. Sakai
Oral presentation, English, 日本金属学会 日本金属学会講演概要集（第135回秋期講演大会）,日本金属学会（第135回秋期講演大会）
2004 - Cu-Fe合金双結晶の温間疲労特性と方位差依存性
千田勇介; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会 日本金属学会講演概要集（第135回秋期講演大会）,日本金属学会（第135回秋期講演大会）
2004 - Mg単結晶の超塑性挙動とその結晶方位依存性
三浦博己; 楊続躍; 酒井拓; 野川久史; 渡辺義見; 三浦誠司
Oral presentation, Japanese, 日本金属学会 日本金属学会講演概要集（第135回秋期講演大会）,日本金属学会（第135回秋期講演大会）
2004 - Cu-Fe-Cr合金の多軸鍛造による大ひずみ加工と微細粒組織の発達
三浦博己; 瀬川泰三; 酒井拓
Oral presentation, Japanese, 日本機械学会 第12回機械材料・材料加工技術講演会集,第12回機械材料・材料加工技術講演会
2004 - 高温加工マグネシウム合金AZ31の焼きなまし特性
楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 第107回軽金属秋季大会講演概要集
2004 - 降温中多軸鍛造を施したマグネシウム合金AZ31の低温超塑性挙動
邢 劼; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 軽金属学会 第107回軽金属秋期大会講演概要集,第107回軽金属秋期大会講演概要集
2004 - Mechanism of Superplastic Behavior of Mg Single Crystals at Elevated Temperature
H. Miura; T. Sakai; H. Nogawa; Y. Yang; Y. Watanabe; S. Miura
Others, English, Extended Abstracts of the MRS(Boston), Extended Abstracts of the MRS(Boston)
2004 - 析出強化Cu-Cr合金の強ひずみ加工による超微細粒組織形成とその機械的性質
三浦博己; 酒井拓
Oral presentation, Japanese, 第43回銅及び銅合金技術研究会講演概要集
Nov. 2003 - 分散強化Cu-SiO2合金のサイクリッククリープによる粒界破壊とそのメカニズム
三浦博己; 酒井拓
Oral presentation, Japanese, 第43回銅及び銅合金技術研究会講演概要集
Nov. 2003 - アルミニウム合金の高温変形中の回復・再結晶
酒井拓
Others, Japanese, 鳥取県地域新生コンソシアム第2回研究会，組織制御委員会資料
Nov. 2003 - 連鋳アルミニウム合金7475の結晶粒微細化加工処理，
酒井拓
Others, Japanese, 鳥取県地域新生コンソシアム第１回研究会，組織制御委員会資料
Sep. 2003 - Cu-SiO2合金双結晶の高温変形と粒界破壊
三浦博己; 酒井拓; 戸田弘之
Oral presentation, Japanese, 日本金属学会平成15年高温材料設計研究会資料
Aug. 2003 - Effect of Strain Rate on Microstructural Evolution in As-Cast 7475 Al Alloy during Hot Deformation
O. Sitdikov; A. Goloborodko; H. Miura; T. Sakai
Oral presentation, Japanese, 日本金属学会平成15年度高温材料設計研究会資料
Aug. 2003 - 銅の高温での動的再結晶/粒界・粒界三重点での動的粒の優先的発現を中心とした最近の研究結果
三浦博己
Oral presentation, Japanese, 材料物質機構講演会資料
Apr. 2003 - 銅合金の強加工プロセスと結晶粒超微細化（依頼講演），
酒井拓
Oral presentation, Japanese, 異業種交流セミナー「高性能化を目指す実用金属材料の超微細組織制御技術の新展開」資料，日本鉄鋼協会
2003 - 微小ボイドを分散させた炭素鋼の高温変形と強度，
三浦博己; 酒井拓; 小比木真; 吉永直樹
Oral presentation, Japanese, 日本鉄鋼協会第145回春季講演大会，材料とプロセス
2003 - Grain Refinement in As-Cast 7475 Al Alloy under Multiaxial Hot Deformation, シンポジュウム「
O. Sitdikov; A. Goloborodko; H. Miura; T. Sakai
Oral presentation, English, 超強ひずみ加工・超高速変形による組織制御と新しい塑性変形機構視点」，日本金属学会講演概要集（第132回春期大会)
2003 - Fe-20%Cr鋼の温間強ひずみ加工に伴う微細粒組織の生成と温度の影響，
臼井健治; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第132回春期大会)
2003 - 純銅の強ひずみ加工後の焼きなまし特性とその温度依存性，
高山明大; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第132回春期大会）
2003 - 酒井拓：AZ31マグネシウム合金の高温変形特性と動的再結晶，
真田昌美; 楊続躍; 三浦博己
Oral presentation, Japanese, 日本金属学会講演概要集（第132回春期大会）
2003 - AZ31マグネシウム合金の降温多軸加工に伴う微細粒組織の生成，
H. Xing; 惣田裕司; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第132回春期大会）
2003 - Fe-32Ni合金の粒界三重点おける優先的動的再結晶の発現，
Sutandyo Andiawarwant; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第132回春期大会）
2003 - 超微細粒材料における熱的安定性に及ぼす第二相粒子の影響，
浜地春佳; 前田展弘; 吉永直樹; 酒井拓; 三浦博己
Oral presentation, Japanese, 日本金属学会講演概要集（第132回春期会）
2003 - 銅の粒界三重線上に生成した動的再結晶のEBSP分析，
椎葉祐介; 三浦博己; 酒井拓; 矢島健司
Oral presentation, Japanese, 日本金属学会講演概要集（第132回春期大会）
2003 - 粒界すべりを伴わない条件下でのCu-SiO2合金双結晶の高温域の疲労特性，
斎藤智嗣; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第132回春期大会）
2003 - 4N銅双結晶の粒界における動的再結晶，
最川亮; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第132回春期大会）
2003 - Cu-SiO2分散強化合金の高温疲労中の粒界破壊とメカニズム
三浦博己; 酒井拓
Oral presentation, Japanese, 日本機械学会材料力学部門講演会論文集 (M&M2003)
2003 - マグネシウム合金の結晶粒微細化と連続動的再結晶
楊続躍; 酒井拓; 三浦博己
Oral presentation, Japanese, 日本金属学会講演概要集（第133回秋期大会）
2003 - Effect of Pass Strain in Hot Multiaxial Forging on Grain Refinement in 7475 Al Alloy
O. Sitdikov; A. Goloborodko; H. Miura; T. Sakai
Oral presentation, Japanese, 日本金属学会講演概要集（第133回秋期大会）
2003 - 分散粒子による粒界すべりの抑止と粒界破壊，
三浦博己; 酒井拓; 戸田弘之
Oral presentation, Japanese, 日本金属学会講演概要集（第133回秋期大会）
2003 - Temperature Effect on Microstructure Development in As-Cast 7475 Al Alloy during ECAE,
A. Golobordko; O. Sitdikov; H. Miura; T. Sakai
Oral presentation, Japanese, 日本金属学会講演概要集（第133回秋期大会）
2003 - 銅の195Kにおける大ひずみ多軸加工下の微細粒の生成
小林千紘; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第133回秋期大会）
2003 - マグネシウム合金AZ31の大ひずみ加工に伴う微細粒組織の生成と機械的性質
邢 劼; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第133回秋期大会）
2003 - 微小ボイドを分散させた炭素鋼の高温変形と強度
三浦博己; 酒井 拓; 小此木真; 吉永直樹
Oral presentation, Japanese, 日本鉄鋼協会, Camp-ISIJ
2003 - BCC/FCCステンレス鋼の多軸鍛造加工に伴う微細粒組織の生成
酒井拓; 三浦博己; 臼井健治
Oral presentation, Japanese, 日本鉄鋼協会第146回秋季講演大会討論会，材料とプロセス
2003 - マグネシウム合金AZ31の大ひずみ加工に伴う微細粒組織の生成と機械的性質
邢 劼; 楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 軽金属学会 第106回軽金属春期大会講演概要集,第106回軽金属春期大会
2003 - 銅の強ひずみ加工プロセスと微細粒組織制御（基調講演），
酒井拓
Oral presentation, Japanese, 第42回銅及び銅合金技術研究会講演大会講演概要集
Nov. 2002 - 粒界三重点での動的再結晶の優先的発現とその誘発因子，
三浦博己; 酒井拓
Oral presentation, Japanese, 第42回銅及び銅合金技術研究会講演大会講演概要集
Nov. 2002 - マグネシュム合金の動的再結晶
楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第130回春期大会），公募シンポジュウム
Mar. 2002 - IF鋼の温間強ひずみ変形に伴う微細粒組織の生成
滝山直樹; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第130回春期大会）
Mar. 2002 - EBSD study of microstructural evolution developed in 7475 Al alloy under hot ECAE
A. Golobordko; H. Miura; T. Sakai
Oral presentation, English, 日本金属学会講演概要集（第130回春期大会）
Mar. 2002 - Ultrafine Grain Formation during Equal Channel Angular Extrusion in Al-Mg-Ac Alloy
O. Sitdikov; T. Sakai
Oral presentation, English, 日本金属学会講演概要集（第130回春期大会）
Mar. 2002 - 粒界上液体粒子の形状解析による銅の[001]ねじれ粒界のすべり量測定
蓮見洋祐; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第130回春期大会）
Mar. 2002 - 銅の静的再結晶挙動に及ぼす分散粒子の影響
斎藤智嗣; 三浦博己; A.Belyakov; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第130回春期大会）
Mar. 2002 - オーステナイト炭素鋼の高温加工再結晶に及ぼす炭素含有量の影響
守谷直樹; 三浦博己; 酒井拓
Oral presentation, Japanese, 材料とプロセス
Mar. 2002 - Fe-20Cr合金の温間強ひずみ変形に伴う微細粒組織生成
臼井直樹; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本鉄鋼協会第143回春期講演大会
Mar. 2002 - 金属材料の結晶粒微細化プロセスと最近の話題，
酒井拓
Oral presentation, Japanese, 住友金属総合技術研究所招待セミナー資料，尼崎
Mar. 2002 - 鉄鋼の動的再結晶と微細粒組織制御，
酒井拓
Oral presentation, Japanese, 学術功績賞受賞講演，日本鉄鋼協会第145回春季講演大会資料
Mar. 2002 - オーステナイト炭素鋼の高温加工再結晶に及ぼす炭素含有量の影響
守谷直樹; 三浦博己; 酒井拓
Oral presentation, Japanese, 材料とプロセス
2002 - IF鋼の温間強ひずみ変形に伴う微細粒組織の生成
滝山直樹; 三浦博己; 酒井拓
Oral presentation, Japanese, 材料とプロセス
2002 - Kinetics of Grain Refinement in a Stainless Steel by Large Strain Deformation
A. Belyakov; T. Sakai; H. Miura; K. Tsuzaki
Oral presentation, English, An Extended Abstracts of ICASS 2002
2002 - Cu-SiO2合金双結晶の高温疲労と粒界破壊のメカニズム，
三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会高温材料設計研究会資料
2002 - マグネシウム合金の結晶粒微細化と動的再結晶，
楊続躍; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会高温材料設計研究会資料
2002 - 粒界三重点おける優先的動的再結晶のメカニズム，
Sutandyo Andiawarwant; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会高温材料設計研究会資料
2002 - 粒界三重点での動的再結晶の優先的発現とその誘発因子，
三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会「材料集合組織研究会」資料
2002 - 粒界三重点おける動的再結晶の発現に及ぼす温度とと粒径の影響，
Sutandyo Andiawarwant; 酒井拓; 三浦博己
Oral presentation, Japanese, 日本金属学会講演概要集（第131回秋期大会）
2002 - Temperature Effect on Microstructure Development in As-Cast 7475 Al Alloy during ECAE,
A. Golobordko; O. Sitdikov; H. Miura; T. Sakai
Oral presentation, English, 日本金属学会講演概要集（第131回秋期大会）
2002 - Grain Refinement in As-Cast 7475 Al Alloy under Hot Deformation,
O. Sitdikov; A. Goloborodko; H. Miura; T. Sakai
Oral presentation, Japanese, 日本金属学会講演概要集（第131回秋期大会）
2002 - 純銅の強ひずみ加工後の焼きなまし特性と熱的安定性，
高山明大; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第131回秋期大会）
2002 - Fe-20%Cr鋼の温間強ひずみ加工に伴う微細粒組織の生成，
臼井健治; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第131回秋期大会）
2002 - Ni-Be合金の高温変形特性とCu添加の影響，
萱沼貴士; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第131回秋期大会）
2002 - Cu-SiO2合金双結晶のサイクリッククリープ挙動と粒界破壊，
三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第131回秋期大会）
2002 - オーステナイト系ステンレス鋼の強ひずみ加工における第二相粒子の影響，
浜地春佳; 酒井拓; 三浦博己
Oral presentation, Japanese, 日本金属学会講演概要集（第131回秋期大会）
2002 - 塑性加工に伴う新粒組織の生成機構－連続／不連続再結晶（基調講演）
酒井拓
Oral presentation, Japanese, 日本金属学会高温材料設計研究会資料
Aug. 2001 - Cu-Si合金双結晶の動的再結晶挙動に及ぼすひずみ速度の影響
三浦博己; 小座間政義; 最川亮; 酒井拓
Oral presentation, Japanese, 日本金属学会高温材料設計研究会資料
Aug. 2001 - 高温加工オーステナイトの回復と再結晶
酒井拓
Oral presentation, Japanese, 新日本製鉄八幡技術研究所招待セミナー資料
May 2001 - Dynamic Recrystallization under Continuous and Discontinuous Reaction (Invited), Recrystallization and Grain Growth
T. Sakai; A. Belyakov; H. Miura
Keynote oral presentation, English, Recrystallization and Grain Growth, eds. G. Gottstein and D. A. Molodov, Springer, International conference
2001 - 銅多結晶の粒界三重点おける動的再結晶挙動
Sutandyo Andiawarwant; 三浦博己; 酒井拓
Oral presentation, Japanese, 日本金属学会講演概要集（第131回春季大会)
Mar. 2000