Shinohara Yuri
| Department of Mechanical and Intelligent Systems Engineering | Associate Professor |
| Cluster III (Fundamental Science and Engineering) | Associate Professor |
Researcher Information
Field Of Study
Career
- Oct. 2023 - Present
The University of Electro-Communications, Graduate School of Informatics and Engineering, School of Informatics and Engineering Department of Mechanical and Intelligent Systems Engineering, Cluster III(Fundamental Science and Engineering), 准教授, Japan - Apr. 2016 - Oct. 2023
Tokyo Institute of Technology, Institute of Innovative Research, 助教 - Apr. 2015 - Mar. 2016
Tokyo Institute of Technology, 精密工学研究所, 助教
Research Activity Information
Paper
- Magnitude of incompatibility between habit plane variants related by 180° rotation
Nozomi Takahashi; Yuri Shinohara; Hiroyuki Kawata; Tomonari Inamura
Proceedings of International Symposia on Steel Science, Iron and Steel Institute of Japan, 2024, 43-48, Nov. 2024, Peer-reviwed
International conference proceedings - Origin of bent ridge-kink based on disclination relaxation
Xueyu Zhang; Ryutaro Matsumura; Yuri Shinohara; Tomonari Inamura
International Journal of Solids and Structures, Elsevier BV, 298, 112829-112829, Jul. 2024, Peer-reviwed, In this study, we have developed a geometric model for bent kinks by introducing sequences of ortho-connected kink bands into ridge-kinks to provide insights into the possible reasons why kinks are bent and the resulting geometry when they are bent. We first formulated the Frank angles and coordinates of the disclinations formed in the bent kinks, which enable our discussion on the influence of the introduction of ortho-kinks on the Gibbs energy by utilizing Romanov's disclination model. It turns out that the introduction of ortho-kinks can relax the elastic strain energy and thus reduce the Gibbs energy of the system under compression states with lower external stresses. On the other hand, the introduction of ortho-kinks increases the Gibbs energy at higher compression stresses, implying sharp ridge-kinks are preferred under such conditions. This trend resembles the experimental observations reported by previous studies that the shapes of newly formed kinks tend to transition from pre-kinks with bent shapes to ridge-kinks with sharp shapes as the compression test progresses. The smoothly bent kink with smoothly distributed misorientation, formed by increasing the number of introduced ortho-kinks, can further reduce the Gibbs energy at lower applied stresses. Subsequently, based on the Rank-1 condition for the connection of kink bands, we further analyzed the geometry of such smoothly bent kinks and derived the analytical equations for the constraints on the orientation distribution. Finally, we conducted EBSD measurements on bent kinks observed in directionally solidified (DS) LPSO-Mg alloys and confirmed that the derived equations for the orientation distribution are in good agreement with the experimental results.
Scientific journal - Peculiar martensitic microstructure and dislocation accumulation behavior in Ti-Ni-Cu shape memory alloys almost satisfying the triplet condition
A. Heima; Y. Shinohara; H. Akamine; M. Nishida; T. Inamura
Acta Materialia, Elsevier BV, 269, 119823-119823, May 2024, Peer-reviwed, Dislocation accumulation behavior at the lattice correspondence variant (CV) triplets of the Ti-Ni-Cu alloy close to the triplet condition (TC) was investigated by using in situ heating transmission electron microscopy observation. The martensitic microstructure of this alloy was peculiar because of no {011}o compound twin laminate as predicted by the phenomenological theory of martensite crystallography. The peculiar martensitic microstructure was composed of a combination of six different CVs connected by twin-relationship, including triplet and quadruple. Other types of triplets with higher incompatibility were not observed. It was revealed that few transformation-induced dislocations associated with thermal cycling were formed at the compatible martensitic microstructure satisfying the TC in the present alloy. The fact that few transformation-induced dislocations are formed in the TC microstructure in the Ti-30Ni-20Cu alloy during thermal cycling explains the good thermal cycling properties of this alloy.
Scientific journal - Local Plastic Deformation of Kink Band Opposing External Stress in Mg–Zn–Y Alloy
Ryutaro Matsumura; Yuri Ueda; Koji Hagihara; Yuri Shinohara; Tomonari Inamura
MATERIALS TRANSACTIONS, Japan Institute of Metals, 65, 1, 101-104, 01 Jan. 2024, Peer-reviwed, In order to determine a factor of kink strengthening, spatial distribution of crystal rotation, kink interface rotation and plastic strain in deformed kink bands was investigated. Fine mesh was drawn on kink microstructure using focused-ion beam to map the plastic strain caused by the further deformation. Results clearly showed the existence of local deformation in the opposite direction of the external stress. This opposing plastic deformation was explained well the observed crystal rotation and rotation of the kink interface, provided that the rank-1 connection was maintained during deformation. The constraint between connected kink bands was suggested to be the origin of this opposite deformation and one of the factors leading to kink strengthening.
Scientific journal, English - Geometry of butterfly martensite in Fe-18Ni-0.7Cr-0.5C alloy
Nozomi Takahashi; Sho Shinozaki; Yuri Shinohara; Yasuaki Tanaka; Hiroyuki Kawata; Tomonari Inamura
ISIJ International, Iron and Steel Institute of Japan, 64, 2, 202-211, Oct. 2023, Peer-reviwed, To clarify the geometry of the junction of martensite which forming butterfly-type martensite, electron microscopy, theoretical analysis using the phenomenological theory of martensite crystallography and rank-1 connection were carried out on Fe-18Ni-0.7Cr-0.5C (mass%) alloy. Martensite plates in this alloy exhibit {252}γ habit plane and K-S OR and are in good agreement with the double shear PTMC by Ross and Crocker. The frequency of formation of V1/V2 and V1/V16 (butterflies) pairs was 20% each, with these two pairs alone accounting for 40% of the total. Theoretical analysis using rank-1 connection of variants revealed that butterfly-pairing is not a geometrically compatible morphology, even for alloys in which butterfly martensite forms frequently. We have also revealed theoretically that the junction plane of the butterfly-pairing keeps (100)γ independent of the mode of lattice invariant shear (i.e. morphology of martensite plate). Preferential formation mechanism for butterfly-pairing is discussed based on the common lattice invariant deformation between V1 and V16.
Scientific journal, English - Analysis of thin-plate martensite microstructure in steel focusing on incompatibility and its visualization
Yuri Shinohara; Mayuko Hishida; Yasuaki Tanaka; Tomonari Inamura
Lead, Acta Materialia, Elsevier BV, 259, 119275-119275, Aug. 2023, Peer-reviwed, The thin-plate martensite microstructure in an Fe-29.50Ni-0.34C (wt%) alloy was analyzed to understand the factors that affect the variant pairing tendency. We focused on the rigid body rotation Ql/k at the variant/variant junction planes derived by the rank-1 connection, because the factor Ql/k corresponds to the incompatibility in the junction plane. Theoretical analysis showed that three types of variant pairs (type I: V1/V17, type II: V1/V6, and type III: V1/V16) had a small degree of incompatibility (θ). These pairs accounted for 70% of the total microstructure. The formation frequency followed the order type II > type I > type III in both thin-plate and lenticular martensite microstructures, applying a correction that makes the factors that reduce the correlation between the observed two-dimensional and actual three-dimensional formation frequencies of the variant pairs irrelevant. For the type III variant pairs, the crystal orientation did not strictly follow the orientation relationship that the invariant plane condition specified. We succeeded in mapping this deviation using data obtained by electron backscatter diffraction (EBSD). Both the deviation angle and axis were well explained by Ql/k. The deviation angle was significant in the vicinity of the junction plane and decreased with distance from the junction plane. Although this could only be visualized for the type III pairs, its detection should be possible in other shape memory alloys through the use of a higher angular resolution for the EBSD measurements. Information regarding the spatial distribution of this incompatibility helps us understand the formation process of the martensite microstructure.
Scientific journal - Corrigendum to ‘Triplet condition: A new condition of supercompatibility between martensitic phases’ [Journal of the Mechanics and Physics of Solids 169 (2022) /105050] (Journal of the Mechanics and Physics of Solids (2022) 169, (S0022509622002289), (10.1016/j.jmps.2022.105050))
Francesco Della Porta; Akira Heima; Yuri Shinohara; Hiroshi Akamine; Minoru Nishida; Tomonari Inamura
Journal of the Mechanics and Physics of Solids, 174, May 2023, The authors regret that there are typographical errors in Theorem 2.1 and Proposition 3.3. The corrected parts are as follows. Theorem 2.1 ( (Chen et al., 2013), Thm. 2). Let [Formula presented]be distinct, [Formula presented]for some [Formula presented] and such that there exist [Formula presented]and [Formula presented]satisfying [Formula presented] Proposition 3.3. Let [Formula presented]be three distinct symmetry related martensite variants and suppose that [Formula presented]is a twin between [Formula presented]and [Formula presented] Then, [Formula presented]has a solution R[Formula presented]O(3), and a, n[Formula presented]for each [Formula presented]if and only if [Formula presented] [Formula presented] The authors would like to apologise for any inconvenience caused.
Scientific journal - Numerical Analysis of Disclinations in Connecting Kink Bands Formed by Multiple Basal Shear
Ryutaro Matsumura; Yuri Shinohara; Tomonari Inamura
MATERIALS TRANSACTIONS, Japan Institute of Metals, 64, 4, 817-826, 01 Apr. 2023, Peer-reviwed, We analyzed the kinematic (geometric) aspects of kink bands with multiple basal shear using rank-1 connection to investigate the type of disclination and annihilation of disclinations in kink microstructures. We found that wedge disclinations occur in connecting kink bands for realistic magnitude of shear that can occur, regardless of the shear direction. The normal vector of the junction plane between kink bands and Frank vector of the resulting wedge-disclination varied continuously with respect to the changes in the magnitude and direction of the basal shear. Annihilation of disclinations is possible even between the kinks which are formed by multiple basal shears. Kinematical model of the three-dimensional wavy kinks are proposed using the obtained results.
Scientific journal, English - Comparison of Dislocation Accumulation Behavior upon Thermal Cycling in Ti-30Ni-20Cu and Ti-39Ni-11Pd Shape Memory Alloys
Akira Heima; Yuri Shinohara; Tomonari Inamura
MATERIALS TRANSACTIONS, Japan Institute of Metals, 65, 3, 352-355, Mar. 2023, Peer-reviwed, Accumulation behavior of transformation-induced dislocation upon thermal cycling of Ti–30Ni–20Cu which satisfies the triplet condition (TC) was compared to that of Ti–39Ni–11Pd which is known as low hysteresis shape memory alloy designed by the condition that the middle eigenvalue of lattice deformation is 1 (CC1). The dislocation density was determined by the Williamson-Hall method. Although the 0.2% proof stress of the Ti–30Ni–20Cu alloy was about half that of the Ti–39Ni–11Pd alloy, the dislocation accumulation behavior was almost the same in both alloys. The formation of transformation-induced dislocation is effectively suppressed by satisfying TC, more than equivalently to satisfying CC1 only. TC is suggested to be a new guideline to design durable shape memory alloy.
Scientific journal, English - Triplet condition: A new condition of supercompatibility between martensitic phases
Francesco Della Porta; Akira Heima; Yuri Shinohara; Hiroshi Akamine; Minoru Nishida; Tomonari Inamura
Journal of the Mechanics and Physics of Solids, Elsevier BV, 169, 105050-105050, Dec. 2022, Peer-reviwed, Enhancing the compatibility of phases and hence reducing the introduction of plastic deformations during phase transitions are crucial to improving the hysteresis and cycling performance of shape memory alloys. We focus here on a new condition of supercompatibility between martensitic variants (called the triplet condition, TC) that allows for the formation of three-fold microstructures and that we believe influences the reversibility of martensitic transformations. Most interesting of all, we show that in the case of cubic-to-orthorhombic phase transformations TC generalizes the cofactor conditions (Chen et al., 2013. Journal of the Mechanics and Physics of Solids 61, 2566-2587.), conditions of supercompatibility between phases that empirically seem to influence reversibility but are extremely difficult to achieve in the design of new materials. We then analyze the martensite microstructure in a sample of Ti-30Ni-20Cu (at%) alloy, which closely satisfies TC, revealing an unusual microstructure comprising two-fold (ordinary twin), three-fold (TC), and four-fold (crossing twin) building blocks connected to each other. We finally discuss the possibility of designing durable shape memory alloys based on TC.
Scientific journal - Analysis of variant-pairing tendencies in lenticular martensite microstructures based on rank-1 connection.
Shinohara Y; Akabane S; Inamura T
Scientific reports, Springer Science and Business Media LLC, 11, 1, 14957, Jul. 2021, Peer-reviwed, Herein, variant-pairing tendencies of lenticular martensite in an Fe–30Ni–0.3C (wt%) alloy are analyzed based on rank-1 connection at martensite/martensite junction planes (JPs) to facilitate the understanding of martensite microstructure. The degree of incompatibility (θ) at the JPs successfully explained their observed frequency; in the actual microstructure, variant pairs with a small θ form preferentially. The experimentally obtained JPs were consistent with theoretical ones. To the best of our knowledge, this is the first study to confirm the validity of variant-pair crystallography in steel based on rank-1 connection, both theoretically and experimentally. Diamond, composite-spear, and composite-kink clusters are considered. The cumulative θ at the JPs can suppress diamond cluster formation because it exceeds the θ of a single variant pair, and the diamond cluster is not observed experimentally. However, θ at the JPs cancel out in composite-spear (CS) and composite-kink (CK) clusters, but CK clusters are rarely observed experimentally, while a few CS clusters are observed. This demonstrates the analytical limitations of 2D approaches used to evaluate the frequency of variant pairs and clusters. These two variant clusters have a narrow window of 2D observation because the orientation relationships between JPs and intersection lines between two habit planes affect the areas of JPs.
Scientific journal - Rank-1 connection of kink bands formed by non-parallel shears
Tomonari Inamura; Yuri Shinohara
Materials Transactions, The Japan Institute of Metals and Materials, 61, 5, 870-874, 01 Apr. 2020, Peer-reviwed, False, The geometry of kink bands with the general shear direction on the unique slip plane was formulated and the connection between two kink bands formed by non-parallel shears on the slip plane was examined using rank-1 connection. For a kink deformation in a metal with a hexagonal lattice, we derived an equation that decomposes the general shear direction into two ©aª basal slips. The rotation axis of the misorientation of kink band moves away rapidly from h0110 = i to h1210 = i as the second ©aª basal shear component increased. We proved that any two kink bands formed by non-parallel basal shears can be rank-1 connected to each other. In addition to the wedge disclination, a mixed disclination at the junction of two kink bands formed by non-parallel basal shears was found.
Scientific journal, English - Goss Orientation Evolution in Ti?5.5Mo?8Al?6Zr Shape Memory Alloy upon Heat Treatment
Yuri Shinohara; Tomoya Sasaki; Masaki Tahara; Hideki HOSODA; Tomonari Inamura
MATER TRANS, JAPAN INST METALS & MATERIALS, Vol. 60, 9, Page 1890-1897, Jun. 2019, Peer-reviwed, The effect of heat treatment temperature on texture formation in Ti-5.5Mo-8Al-6Zr (mol%) alloy sheets was systematically investigated in this study. alpha '' martensite was induced by cold-rolling. Although the deformation texture of alpha '' martensite could not be detected, the formation of {130}(alpha '') < 3 (1) over bar0 >(alpha '') and (100)(alpha '')[010](alpha '') textures was proposed. The specimen heat-treated at 1073K or higher consisted of a single beta phase, and Goss, {110}(beta) < 113 >(beta), and Brass orientations were formed as the recrystallization textures. The Goss orientation, which is irregular for beta-Ti alloys, developed with increasing heat treatment temperature, and became the dominant component in the specimens heat-treated at 1173 K. The specimen heat-treated at 973K consisted of the beta + alpha phase. {113}(beta)< 110 >(beta), {113}(beta) < 141 >(beta), {223}(beta)< 252 >(beta), {223}(beta)< 692 >(beta), and {332}(beta) < 113 >(beta) were formed in the beta phase, whereas {11 (2) over bar0}(alpha)< 1 (1) over bar 00 >(alpha) {11 (2) over bar2}(alpha) < 1 (1) over bar 00 >(alpha) was formed in the phase. Transmission electron microscopy observations revealed that the specimen heat-treated at 973K was not completely recrystallized. This microstructural difference led to a difference in texture components between the specimens heat-treated at 973K and at 1073K or higher.
Scientific journal, English - Development of < 001 >-fiber texture in cold-groove-rolled Ti-Mo-Al-Zr biomedical alloy
Yuri Shinohara; Yoshiki Matsumoto; Masaki Tahara; Hideki Hosoda; Tomonari Inamura
MATERIALIA, ELSEVIER SCI LTD, 1, No., 52-61, Sep. 2018, Peer-reviwed, The < 001 >(beta)-fiber texture, which is a highly desirable orientation for beta-Ti alloys with low Young's modulus, was formed successfully in cold-groove-rolled Ti-5.5Mo-8Al-6Zr (mol.%) alloy wires. The effect of a reduction in the cross-sectional area (CSA) on the evolution of the rolling and recrystallization texture, as well as the Young's modulus, was systematically investigated. The formation of alpha''-martensite was induced by the cold-groove-rolling process, with a < 010 >(alpha'')-fiber texture developing in specimens with CSA reductions of 93% or more. This texture corresponds to the < 110 >(beta)-fiber texture considering the lattice correspondence of the martensitic transformation between the beta (bcc) - and alpha''(orthorhombic)-phases. The < 001 >(beta)-fiber recrystallization texture was formed in solution-treated specimens with CSA reductions of 80% or more and developed dramatically with a reduction of 98%. The development of the < 001 >(beta)-fiber texture as the dominant component has not been reported previously in conventional beta-Ti alloys, although the < 001 >(beta)-fiber texture is the same as the deformation texture of conventional bcc alloys. The Young's modulus of the solution-treated specimens along the rolling direction decreased with an increase in the CSA reduction rate. This was attributed to the development of the < 001 >(beta)-fiber texture.
Scientific journal, English - Anisotropy of Young's Modulus in a Ti-Mo-Al-Zr Alloy with Goss Texture
Yuri Shinohara; Daiki Narita; Masaki Tahara; Hideki Hosoda; Tomonari Inamura
MATERIALS TRANSACTIONS, Japan Institute of Metals, 57, 12, 1998-2001, Aug. 2016, Peer-reviwed, Anisotropy of the Young's modulus and microstructure of a recrystallized β Ti-Mo-Al-Zr alloy with a Goss texture were investigated. Specimens were solution-treated at 1173 K for 3.6 ks after cold rolling with a reduction rate of 99%. The {011}<100> Goss recrystallization texture developed as a major texture component. The Young's modulus was evaluated by tensile tests using a strain gage method. Anisotropy of the Young's modulus depending on the loading direction was observed: The lowest and highest values of the Young's modulus were 44 and 77 GPa, respectively. The compliance anisotropy factor, J, and the characteristic modulus, S11, of the alloy were calculated from the measured Young's moduli and the volume fractions of the texture components.
Scientific journal - Effect of heat treatment temperature on microstructure and hardness of Zr-9mol%Au near-eutectoid alloy
H. Hosoda; T. Ishigaki; Y. Shinohara; T. Inamura
Journal of the Japan Institute of Metals, JAPAN INST METALS & MATERIALS, Vol. 80, 1, pp. 77-84, Jan. 2016, Peer-reviwed, In order to develop new functional biomaterials, the Zr-Au alloy system was focused and a Zr-9 mol%Au near-eutectoid alloy was used in this work. Effect of solution treatment and aging treatment temperatures on phase constituent, microstructure and Vickers hardness was investigated. It was found that Zr-9 mol%Au is a hypereutectic composition and experimental results in this work are not in agreement with the experimental phase diagram reported by Lomello-Tafin et al., but in good agreement with the calculated phase diagram reported Su et al. The major apparent phase was hcp alpha Zr regardless of the heat treatment condition and Zr3Au second phase precipitated when heat-treated at 1173 K or lower temperatrues. The Vickers hardness value was HV503 after the solution treatment at 1273 K, but became lower with increasing the amount of micrometer-size-Zr3Au precipitates. The hardness of this alloy was mainly due to the amount of the solute Au in alpha Zr matrix. However, the alloy was slightly hardened by aging at 673 K due to the formation of submicron-meter-size fine Zr3Au precipitates.
Scientific journal, English - Texture and mechanical property of TiMoAlZr biomedical shape memory alloy
Daiki Narita; Yuri Shinohara; Masaki Tahara; Hideki Hosoda; Tomonari Inamura
PFAM24(Processing and Fabrication of Advanced Materials - XXIV), Vol. 1, Dec. 2015
Scientific journal, English - Effect of Sn content on phase constitution and mechanical properties of Ti-Cr-Sn shape memory alloys
N. Okano; Y. Shinohara; Y. Kusano; M. Tahara; T. Inamura; S. Miyazaki; H. Hosoda
MATERIALS TODAY-PROCEEDINGS, ELSEVIER SCIENCE BV, 2, 825-828, Nov. 2015, Peer-reviwed, The effect of Sn content on the phase constitution and mechanical properties of Ti-6Cr-Sn ( mol%) alloy as investigated. Both Ti-6Cr-5Sn and Ti-6Cr3Sn alloys were beta single phase at room temperature. Though increase in the Sn content to 5% was effective in increasing the ultimate tensile strength and yield stress, it sharply decreased the fracture strain and eliminated the superelastic recovery strain. The diffraction peaks of alpha '' martensite phase appeared in the XRD profile of Ti-6Cr-3Sn alloy after the tensile deformation, while not in the Ti-6Cr-5Sn alloy. These results indicate that the Sn addition decreases martensitic transformation temperature. (C) 2015 The Authors. Published by Elsevier Ltd.
International conference proceedings, English - Deformation behavior of Ti-4Au-5Cr-8Zr superelastic alloy with or without containing Ti3Au precipitates
Y. Shinohara; M. Tahara; T. Inamura; S. Miyazaki; H. Hosoda
MATERIALS TODAY-PROCEEDINGS, ELSEVIER SCIENCE BV, 2, 821-824, Nov. 2015, Peer-reviwed, Ti-Au-Cr-Zr alloys have been developed as novel Ni-free shape memory and superelastic alloys. In this study, the effect of heat treatment temperature on the precipitation behavior of Ti3Au and superelasticity of Ti-4Au-5Cr-8Zr (mol %) alloy was investigated by theta-2 theta X-ray diffraction measurement (XRD), scanning electron microscopy (SEM) observation and tensile tests. Ti3Au precipitates were formed homogenously in beta (bcc) matrix in the specimen heat-treated at 1073 K, whereas only phase was observed in the specimen heat-treated at 1173 K. Although both the specimens with or without containing Ti3Au precipitates exhibited superelasticity at room temperature, better superelasticity was observed when Ti3Au precipitates were formed by the heat treatment at 1073 K. Based on the evaluation of residual plastic strains after applying a constant maximum stress of 370MPa at room temperature, the precipitation of Ti3Au formed at 1073 K was effective to reduce plastic deformation, resulting in good room temperature superelasticity in Ti-4Au-5Cr-8Zr alloy with containing Ti3Au precipitates. (C) 2015 The Authors. Published by Elsevier Ltd.
International conference proceedings, English - Effect of Annealing Temperature on Texture Formation of Ti-4Au-5Cr-8Zr Biomedical Superelastic Alloy
Yuri Shinohara; Masaki Tahara; Tomonari Inamura; Hideki Hosoda
Journal of the Japan Institute of Metals, Japan Institute of Metals, 80, 1, 45-50, Nov. 2015, Peer-reviwed, The effect of annealing temperature on texture formation associated with superelastic behavior is clarified of Ti-4Au-5Cr-8Zr biomedical alloy in which Ti3Au precipitates at 973 Kand 1073 Kbut does not precipitate at 1173 K. A Ti-4Au-5Cr-8Zr alloy ingot was cold-rolled with a reduction up to 98% in thickness followed by annealing at 973, 1073 and 1173 K for 1.8 ks. It was found that the as-rolled alloy and the alloy annealed at 973 K exhibit {112}β<110>β rolling texture, while the alloys annealed at 1073 K and 1173 K exhibit {001}β<110>β recrystallization texture regardless of Ti3Au precipitates. {001}β<110>β texture develops stronger in the alloy annealed at 1173 K compare with the alloy annealed at 1073 K. This is one of the reasons why alloy annealed at 1173 K shows larger shape recovery strain than the alloy annealed at 1073 K when tensile strain is applied along the rolling direction.
Scientific journal - Shape Memory Behavior of Ti-Au-Cr Biomedical Alloy
Hideki Hosoda; Takuya Ishigaki; Yuri Shinohara; Tomonari Inamura; Kenji Goto; Shuichi Miyazaki
Proceedings of the 13th World Conference on Titanium, pp. 1695-1698, Aug. 2015, Peer-reviwed
Scientific journal, English - Ti-4Au-5Cr-8Zr 超弾性合金の開発とその変態挙動に関する研究
篠原百合
Mar. 2015
Doctoral thesis, Japanese - Effect of Annealing Temperature on Microstructure and Superelastic Properties of Ti-Au-Cr-Zr Alloy
Yuri Shinohara; Masaki Tahara; Tomonari Inamura; Shuichi Miyazaki; Hideki Hosoda
MATERIALS TRANSACTIONS, Japan Institute of Metals, 56, 3, 404-409, Jan. 2015, Peer-reviwed, Effect of annealing temperature on microstructure and superelasticity of Ti-4Au-5Cr-8Zr (mol%) was investigated. Only β phase was observed in the specimen annealed at 1173 K, whereas the precipitation of Ti3Au, Zr33Ti40Au27 (Laves phase) and α phase occurred in the specimens annealed below 1073 K. Superelasticity was clearly observed in the specimens annealed at 1073K and 1173 K, though it was absent in the specimens annealed at 873K and 973 K. The maximum superelastic recovery strain was increased by the precipitation of Ti3Au in the specimen annealed at 1073 K. This is due to the increase in the critical stress for slip by the precipitation strengthening effect of Ti3Au.
Scientific journal - Wide-range temperature dependences of Brillouin scattering properties in polymer optical fiber
Kazunari Minakawa; Neisei Hayashi; Yuri Shinohara; Masaki Tahara; Hideki Hosoda; Yosuke Mizuno; Kentaro Nakamura
Japanese Journal of Applied Physics, IOP Publishing, 53, 4, 042502-042502, 27 Mar. 2014, Peer-reviwed, We investigate the temperature dependences of the Brillouin scattering properties in a perfluorinated graded-index (PFGI-) polymer optical fiber (POF) in a wide temperature range from −160 to 125 °C. The temperature dependences of the Brillouin frequency shift, linewidth, and Stokes power are almost linear at lower temperature down to −160 °C; while they show nonlinear dependences at higher temperature. These behaviors appear to originate from the partial glass transition of the polymer material.
Scientific journal - Evaluation of Brillouin scattering properties in plastic optical fibers for wide-range temperature sensing
K. Minakawa; N. Hayashi; Y. Shinohara; M. Tahara; H. Hosoda; Y. Mizuno; K. Nakamura
Technical Digest of the 18th Microoptics Conference, MOC 2013, Dec. 2013, Peer-reviwed, We investigate the temperature dependence of Brillouin scattering properties in perfluorinated graded-index (PFGI-) plastic optical fibers (POFs) in a wide temperature range from -170 to 130°C. The temperature dependence of Brillouin frequency shift is found to be nonlinear at > 84°C; while it shows linear dependences even at -170°C. The Stokes power is maximal at 60 °C and is gradually reduced with decreasing or increasing temperature. Our results indicate that the Brillouin scattering in PFGI-POFs can be exploited to cryogenic-temperature sensing as well as higher-temperature sensing. © 2013 The Japan Society of Applied Physics.
International conference proceedings, English - Wide-range temperature dependence of brillouin frequency shift in plastic optical fiber
K. Minakawa; N. Hayashi; Y. Shinohara; M. Tahara; H. Hosoda; Y. Mizuno; K. Nakamura
Proceedings of 22nd International Conference on Plastical Optical Fibers, POF 2013, 72-75, Jan. 2013, Peer-reviwed, We investigate the temperature dependences of the Brillouin scattering properties in a perfluorinated graded-index (PFGI-) plastic optical fiber (POF) in a wide temperature range from-160 to 125 °C. The temperature dependences of the Brillouin frequency shift, linewidth, and Stokes power are linear at lower temperature down to-160 °C; while they show nonlinear dependences at higher temperature. These behaviors appear to originate from the partial glass transition of the polymer material.
International conference proceedings, English - Phase Constituents of Ti-Cr-Au and Ti-Cr-Au-Zr Alloy Systems
Yuri Shinohara; Takuya Ishigaki; Tomonari Inamura; Hiroyasu Kanetaka; Shuichi Miyazaki; Hideki Hosoda
PRICM 7, PTS 1-3, TRANS TECH PUBLICATIONS LTD, 654-656, 2122-+, 2010, Peer-reviwed, The phase constituents of the Ti-Cr-Au ternary and Ti-Cr-Au-Zr quaternary systems were investigated using X-ray diffraction analysis and optical microscopy. The composition ranges were 3 similar to 10mol%Cr and 0 similar to 8mol%Au for the ternary system, and 0 similar to 42mol%Zr were added to Ti-5mol%Cr-4mol%Au. It was found that the beta phase was stabilized by the addition of Cr and Zr, and that A15-type Ti3Au was formed when the Au content was 6mol% or higher. Besides, C14 Laves phase similar to Zr33Ti40Au27 was recognized in Ti-5mol%Cr-4mol%Au-42mo1%Zr.
International conference proceedings, English
MISC
- Effect of Heat Treatment Temperature on Microstructure and Superelastic Properties of Ti-4Au-5Cr-8Zr Biomedical Superelastic Alloy
篠原 百合
日本チタン協会, Oct. 2016, チタン = Titanium Japan, 64, 4, 304-309, Japanese, 1341-1713, 40020998711, AN10468673 - The Microstructure and Mechanical Properties of Ti-Au-Ta and Ti-Au-Cr-Ta Biomedical Alloys
FUCHIWAKI Kota; SHINOHARA Yuri; GOTO Kenji; TAHARA Masaki; INAMURA Tomonari; MIYAZAKI Shuichi; HOSODA Hideki
The Japan Society of Mechanical Engineers, 07 Nov. 2013, The Proceedings of the Materials and processing conference, 2013, 0, _212-1_-_212-2_, Japanese, 201402221664944985, 110009935834, AA11902467 - プラスチック光ファイバ中のブリルアン周波数シフトの広域温度依存性
皆川和成; 林寧生; 篠原百合; 田原正樹; 細田秀樹; 水野洋輔; 中村健太郎
2013, 応用物理学会秋季学術講演会講演予稿集(CD-ROM), 74th, 201302271284543678
Lectures, oral presentations, etc.
- Analysis of Martensite Microstructure Formation at Annealing Twin in an Fe-30Ni0.3C alloy
Yuri Shinohara; Tomonari Inamura
Poster presentation, The 9th International Symposium on Biomedical Engineering (ISBE2024)
04 Dec. 2024
03 Dec. 2024- 04 Dec. 2024 - Spatial distribution of incompatibility in thin-plate martensite microstructure of steel
Yuri Shinohara; Mayuko Hishida; Yasuaki Tanaka; Tomonari Inamura
Poster presentation, The 7th International Symposium on Steel Science 2024, Peer-reviewed
12 Nov. 2024
11 Nov. 2024- 14 Nov. 2024 - Change in variant pairs with progression of transformation in lath martensite
Nozomi Takahashi; Yuri Shinohara; Hiroyuki Kawata; Tomonari Inamura
Poster presentation, The 7th International Symposium on Steel Science 2024, Peer-reviewed
12 Nov. 2024
11 Nov. 2024- 14 Nov. 2024 - Specificity and universality in variant pairings of lath, butterfly, lens and thin-plate martensites: perspective from geometrical theory
Tomonari Inamura; Nozomi Takahashi; Yuri Shinohara; Hiroyuki Kawata; Yasuaki Tanaka
Keynote oral presentation, The 7th International Symposium on Steel Science 2024, Invited, Peer-reviewed
12 Nov. 2024
11 Nov. 2024- 14 Nov. 2024 - Ti-Ni合金におけるB19'マルテンサイトの自己調整組織に及ぼすNi濃度の影響
彦坂 元; 赤嶺 大志; 篠原 百合; 西田稔; 稲邑 朋也
Poster presentation, 第14回 SMAシンポジウム2024
03 Oct. 2024
03 Oct. 2024- 04 Oct. 2024 - Triplet条件を満たす形状記憶合金のマルテンサイト組織の形成・消滅過程
井上 ひかり; 彦坂 元; 松村 隆太郎; 篠原 百合; 稲邑 朋也
Poster presentation
03 Oct. 2024
03 Oct. 2024- 04 Oct. 2024 - EBSD測定データを活用したFe-Ni-C合金におけるマルテンサイト組織の解析
篠原百合
Keynote oral presentation, 第14回 SMAシンポジウム2024, Invited
03 Oct. 2024
03 Oct. 2024- 04 Oct. 2024 - Triplet条件を満たすTi-Ni系合金におけるマルテンサイト正・逆変態過程
井上 ひかり; 平間 慧; 彦坂 元; 松村 隆太郎; 篠原 百合; 稲邑 朋也
Oral presentation, 日本金属学会第175回講演大会, Peer-reviewed
19 Sep. 2024
18 Sep. 2024- 20 Sep. 2024 - Fe-Ni-Cr-C合金におけるラスマルテンサイト変態過程のその場観察
青木 渉; 高橋 希; 松村 隆太郎; 篠原 百合; 川田 裕之; 稲邑 朋也
Poster presentation, 日本金属学会第175回講演大会, Peer-reviewed
18 Sep. 2024
18 Sep. 2024- 20 Sep. 2024 - 薄板状マルテンサイトにおけるバリアント結合則の旧γ粒径依存性
江藤 優吾; 高橋 希; 篠原 百合; 松村 隆太郎; 川田 裕之; 稲邑 朋也
Poster presentation, 日本金属学会第175回講演大会, Peer-reviewed
18 Sep. 2024
18 Sep. 2024- 20 Sep. 2024 - 晶癖面バリアントペアのrank-1接続条件に対する包括的な理解
高橋 希; 松村 隆太郎; 篠原 百合; 川田 裕之; 稲邑 朋也
Oral presentation, 日本金属学会第175回講演大会, Peer-reviewed
18 Sep. 2024
18 Sep. 2024- 20 Sep. 2024 - 底面すべりと柱面すべりによって形成されたキンク同士の結合状態
張 雪禹; 松村 隆太郎; 篠原 百合; 稲邑 朋也
Oral presentation, 日本金属学会第175回講演大会, Peer-reviewed
18 Sep. 2024
18 Sep. 2024- 20 Sep. 2024 - 湾曲したリッジキンクに関するエネルギー論的考察
張雪禹; 松村隆太郎; 篠原百合; 稲邑 朋也
Oral presentation, 日本金属学会 第174回春期講演大会, Peer-reviewed
15 Mar. 2024
12 Mar. 2024- 15 Mar. 2024 - Ti-Niにおける自己調整組織のNi濃度依存性とその支配因子
彦坂元; 副島洋平; 赤嶺大志; 篠原百合; 西田稔; 稲邑朋也
Oral presentation, 日本金属学会 第174回春期講演大会, Peer-reviewed
14 Mar. 2024
12 Mar. 2024- 15 Mar. 2024 - ラスマルテンサイトにおける変態の進行に伴うバリアント結合則の変化
高橋希; 篠原百合; 川田裕之; 稲邑朋也
Oral presentation, 日本金属学会 第174回春期講演大会, Peer-reviewed
13 Mar. 2024
12 Mar. 2024- 15 Mar. 2024 - 鉄鋼材料の薄板状マルテンサイト組織におけるバリアントペア内部の組織解析
篠原百合
Keynote oral presentation, 日本金属学会 第174回春期講演大会, Peer-reviewed
13 Mar. 2024
12 Mar. 2024- 15 Mar. 2024 - γ粒界に形成する薄板状マルテンサイトのバリアントペアにおける結合則
篠原百合; 佐橋侑馬; 稲邑朋也; 田中泰明
Oral presentation, 日本鉄鋼協会第186回秋季講演大会, Peer-reviewed
20 Sep. 2023
20 Sep. 2023- 22 Sep. 2023 - α’-マルテンサイトにおける(100)γを結合面とするバタフライ型バリアントペアの普遍性
高橋希; 篠崎翔; 篠原百合; 稲邑朋也; 川田裕之
Oral presentation, 日本鉄鋼協会第186回秋季講演大会, Peer-reviewed
20 Sep. 2023
20 Sep. 2023- 22 Sep. 2023 - Fe-Ni-C合金の応力誘起マルテンサイトによる形状記憶効果におよぼすマルテンサイト形態の影響
目黒 まりん; 北尾 崇郎; 篠原 百合; 稲邑 朋也
Poster presentation, 日本金属学会第173回秋期講演大会, Peer-reviewed
19 Sep. 2023
19 Sep. 2023- 22 Sep. 2023 - マルテンサイト組織の適合条件を調整したTiNi基形状記憶合金におけるMsの熱サイクル数依存性
高田 龍平; 平間 慧; 篠原 百合; 稲邑 朋也
Poster presentation, 日本金属学会第173回秋期講演大会, Peer-reviewed
19 Sep. 2023
19 Sep. 2023- 22 Sep. 2023 - TiNiCuHf形状記憶合金におけるマルテンサイト変態過程のその場観察
井上 ひかり; 平間 慧; 篠原 百合; 稲邑 朋也
Poster presentation, 日本金属学会第173回秋期講演大会, Peer-reviewed
19 Sep. 2023
19 Sep. 2023- 22 Sep. 2023 - α’-マルテンサイトバリアントが rank-1接続可能なγ粒界方位差
高橋希; 稲邑朋也; 篠原百合; 川田裕之
Oral presentation, 日本鉄鋼協会 第185回春季講演大会, Peer-reviewed
10 Mar. 2023
08 Mar. 2023- 10 Mar. 2023 - キンクバンドのせん断により発生する回位四重極子と連携変形
松村隆太郎; 上田佑理; 篠原百合; 稲邑朋也
Oral presentation, 日本金属学会 第172回春期講演大会, Peer-reviewed
09 Mar. 2023
07 Mar. 2023- 10 Mar. 2023 - Ti-30Ni-20Cu 形状記憶合金におけるマルテンサイトバリアント間の方位関係
平間慧; 篠原百合; 稲邑朋也
Oral presentation, 日本金属学会 第172回春期講演大会, Peer-reviewed
09 Mar. 2023
07 Mar. 2023- 10 Mar. 2023 - 結合したキンクバンドのせん断により発生する回位多重極子の弾性エネルギー
松村隆太郎; 上田佑理; 篠原百合; 稲邑朋也
Oral presentation, 日本金属学会 第171回秋期講演大会
23 Sep. 2022
20 Sep. 2022- 23 Sep. 2022 - Ti-30Ni-20Cu合金においてマルテンサイト変態により形成される転位組織
平間慧; 篠原百合; 稲邑朋也
Oral presentation, 日本金属学会 第171回秋期講演大会
22 Sep. 2022
20 Sep. 2022- 23 Sep. 2022 - Triplet 条件を満たす TiNiCu 合金の形状記憶特性に及ぼす加工熱処理の影響
半田俊喜; 平間慧; 篠原百合; 稲邑朋也
Poster presentation, 日本金属学会 第171回秋期講演大会, Peer-reviewed
20 Sep. 2022
20 Sep. 2022- 23 Sep. 2022 - TiNi合金のB19’マルテンサイトの晶癖面における塑性緩和の運動学的解析
彦坂元; 平間慧; 篠原百合; 赤嶺大志; 西田稔; 稲邑朋也
Poster presentation, 日本金属学会 第171回秋期講演大会, Peer-reviewed
20 Sep. 2022
20 Sep. 2022- 23 Sep. 2022 - LPSO型Mg合金の二重圧縮試験におけるキンク組織変化と変形挙動
上田佑理; 松村隆太郎; 篠原百合; 宮澤知孝; 藤居俊之; 稲邑朋也
Poster presentation, 日本金属学会 第171回秋期講演大会, Peer-reviewed
20 Sep. 2022
20 Sep. 2022- 23 Sep. 2022 - Ti-Ni-Cu形状記憶合金における特異なマルテンサイト組織
平間慧; Della Porta Francesco; 篠原百合; 西田稔; 稲邑朋也
Poster presentation, 日本金属学会 第169回秋期講演大会, Peer-reviewed
14 Sep. 2021
14 Sep. 2022- 17 Sep. 2022 - Fe-Ni-Cr-C合金におけるラスマルテンサイトのバリアント結合則
高橋希; 篠原百合; 稲邑朋也; 田中泰明; 諏訪嘉宏
Poster presentation, 日本金属学会 第169回秋期講演大会, Peer-reviewed
14 Sep. 2021
14 Sep. 2022- 17 Sep. 2022 - Ridgeキンクにおける区分的に均一なキンク列による回位の緩和
張雪禹; 松村隆太郎; 篠原百合; 稲邑朋也
Poster presentation, 日本金属学会 第170回春期講演大会, Peer-reviewed
22 Mar. 2022
15 Mar. 2022- 22 Mar. 2022 - キンクバンドのせん断により発生する回位多重極子の弾性エネルギー
松村隆太郎; 篠原百合; 稲邑朋也
Oral presentation, 日本金属学会 第170回春期講演大会, Peer-reviewed
16 Mar. 2022
15 Mar. 2022- 22 Mar. 2022 - Compatibility condition at triple junction of martensite and unusual microstructure in TiNiCu alloy
T. Inamura; F. D. Porta; A. Heima; Y. Shinohara; H. Akamine; M. Nishida
Oral presentation, ICOMAT2022, Peer-reviewed
15 Mar. 2022
13 Mar. 2022- 18 Mar. 2022 - Variant Pairings of Lenticular Martensite in Fe-Ni-C Alloy
Y. Shinohara; S. Akabane; T. Inamura
Oral presentation, ICOMAT2022, Peer-reviewed
14 Mar. 2022
13 Mar. 2022- 18 Mar. 2022 - Σ3粒界におけるレンズマルテンサイトのバリアント結合則
篠原百合; 赤羽里夢; 稲邑朋也
Oral presentation, 日本鉄鋼協会 第182回秋季講演大会, Peer-reviewed
17 Sep. 2021
15 Sep. 2021- 17 Sep. 2021 - キンクバンドのせん断により発生する回位多重極子
松村隆太郎; 篠原百合; 稲邑朋也
Oral presentation, 日本金属学会 第169回秋期講演大会, Peer-reviewed
17 Sep. 2021
14 Sep. 2021- 17 Sep. 2021 - キンク組織とその変形に関する運動学的考察
稲邑朋也; 松村隆太郎; 張雪禹; 篠原百合
Keynote oral presentation, 日本金属学会 第169回秋期講演大会, Peer-reviewed
17 Sep. 2021
14 Sep. 2021- 17 Sep. 2021
Research Themes
- 応力誘起マルテンサイト変態の新展開：変態界面での弾性緩和による結晶学的組織最適化
田原 正樹; 篠原 百合
日本学術振興会, 科学研究費助成事業, 東京工業大学, 基盤研究(B), Coinvestigator, 24K01210
Apr. 2024 - Mar. 2027 - マルテンサイト組織の三次元解析によるバリアント結合則の本質的評価
篠原 百合
日本学術振興会, 科学研究費助成事業 若手研究, 東京工業大学, 若手研究, 本課題では鉄合金のバリアント結合則(以下，結合則)を明らかにするために，変形の連続条件(rank-1接続)を軸としてバリアントペアの形成優先度を予測する手法を確立する．レンズマルテンサイトのミドリブや薄板状マルテンサイトの結晶学は，晶癖面における不変面条件で説明できることが知られている．しかしrank-1接続の観点からは，バリアント同士が結合するときに，結合面において不変面条件からの偏差が生じる． 前年度は，レンズマルテンサイトについて不変面条件からの偏差と結合頻度の関係を調査した．本年度は薄板状マルテンサイトが形成するFe-Ni-C合金について，旧γ粒内におけるバリアント結合傾向の二次元解析とシリアルセクショニングを行った． 解析の結果，結合面に生じる不変面条件からの偏差が小さなペア(3種類)が高頻度に形成されることが明らかになった．これはレンズマルテンサイトの場合と同様の結果である．EBSDの測定データを用いて，バリアントペアの内部に存在する不変面条件からの偏差を可視化した．偏差は二つのバリアントの結合面付近で最大となり，結合面から離れると減少した．偏差によって生じる回転軸と回転量はrank-1接続から要請される理論値とほぼ一致した． シリアルセクショニングに適切なγ粒径，マルテンサイト体積分率を有する試料の作製方法を探索の後，シリアルセクショニング-光学顕微鏡法によりスライス画像を取得した．観察領域は500μm×300μm×100μmである． 三次元像の構築には光学顕微鏡写真に対して，バリアントの同定及びバリアント毎に色を塗り分ける必要がある．そのため現在効率化を図るべく，塗分けを支援するプログラムを作成中である．, 20K15046
01 Apr. 2020 - 31 Mar. 2023 - A study of beta titanium superelastic alloys with small transformation stress change during cyclic deformation
Shinohara Yuri
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Tokyo Institute of Technology, Grant-in-Aid for Young Scientists (B), Effect of ω phase on pseudoelasticity in β-Ti alloys was investigated in this study. Cyclic loading-unloading tensile tests were performed at various temperatures using special alloy; volume fraction of ω phase of this alloy is not affected by deformation temperature. Stress for inducing martensite decreases as cycle number at the range of -115 ～ 120℃ increases. Stress for reverse transformation also decreases as cycle number at -115℃ increases. These results imply that shuffling magnitude of ω phase affects pseudoelasticity of β-Ti alloy. Quantitative evaluation of shuffling magnitude was attempted by pair distribution function (PDF) analysis., 17K14833
01 Apr. 2017 - 31 Mar. 2020 - Quest for fundamental dynamics of domain homo interface in shape change materials and principles for high performance materials
HOSODA Hideki; KANETAKA hiroyasu; CHANG tsu-fu mark; SHINOHARA yuri; CHERNEMKO volodymyr
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Tokyo Institute of Technology, Grant-in-Aid for Scientific Research (S), In shape-change materials such as shape memory alloys and piezoelectric materials used for medical and energy applications, external fields such as force and magnetic field and material functions are deeply related each other。 The origin of the shape change is the domain rearrangement and phase transformation due to the motion of domain homo interface. In order to improve the material functions, the structure and dynamics of the domain homo interface have been clarified for the smooth motion with low friction. Principles for the control of interface structure and lattice softening from the first principle calculations have been established to reduce the friction of motion for the enhancement of higher functionality. Moreover, several multifunctional and high performance new shape change materials have been developed., 26220907
30 May 2014 - 31 Mar. 2019 - Design principle and development of super-long life shape memory alloy based on Nitinol
Inamura Tomonari; HOSODA Hideki; TAHARA Masaki; SHINOHARA Yuri; KISE Sumio; YAMASHITA Fumiyoshi; FUJII Misato
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Tokyo Institute of Technology, Grant-in-Aid for Scientific Research (B), Effects of the magnitude of incompatibility at domain-walls in martensite microstructure of Ti-Ni based shape memory alloys were investigated in this study.Numerical analysis on the incompatibility of domain-walls showed that the incompatibility can be vanished or very small at certain kinds of domain-boundary in Ti-Ni based alloys with B2-B19 or B2-B19' martensitic transformation. One of the alloys which satisfies the condition for the very small incompatibility exhibited no shift in transformation temperature upon thermal cycling more than 200 cycles. This result implies that the super-long life shape memory alloy can be developed in Ti-Ni based alloys., 15H04143
01 Apr. 2015 - 31 Mar. 2018 - Mechanism of pseudoelasticity in a beta-titanium shape memory alloy with a wide working temperature range
Shinohara Yuri
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity Start-up, Tokyo Institute of Technology, Grant-in-Aid for Research Activity Start-up, In this study, anomalous temperature dependence of pseudoelasticity in a β-titanium alloy, was investigated from a standpoint of small particles of the ω phase in the matrix, and in terms of phase stability. It was revealed that (1) the martensite was not formed by cooling at -260℃ without stress and (2) the matrix transformed to the martensite and the ω phase disappeared when exposed to stress., 15H06206
28 Aug. 2015 - 31 Mar. 2017 - 生体用チタン合金の六方晶マルテンサイトによる超弾性発現機構の解明と展開
篠原 百合
日本学術振興会, 科学研究費助成事業 特別研究員奨励費, 東京工業大学, 特別研究員奨励費, Ti-Niに匹敵する巨大超弾性歪みの発現を実現するために，大きな格子変形歪みを持つTi-Au-Cr-Zr合金に着目した．前年度は冷却で形成されるマルテンサイトの結晶構造と，応力負荷によって誘起させたマルテンサイトの内部組織を明らかにした．その結果，本合金を冷却することによって形成されるマルテンサイトは，格子定数比b/aの値が六方晶のそれに近い斜方晶マルテンサイトであることが明らかになり，母相と応力誘起マルテンサイト内部でathermal Omega相の分布状態が異なることを明らかにした．本年度は，応力誘起させたマルテンサイトの詳細な内部組織観察を行った． 電子回折図形を解析した結果，応力誘起マルテンサイトの格子定数比b/aは1.67であり，冷却で形成されるマルテンサイトと同様に，六方晶(b/a=1.73)に近い斜方晶マルテンサイトであることが明らかになった．また，母相内部では急冷によって形成される粒状のathermal Omega相(六方晶)とathermal Omega相に由来する散漫散乱が観察された．athermal Omega相の粒径は5nm程度であった．一方，応力誘起したマルテンサイトの内部ではathermal Omega相が観察されず，対応する位置に散漫散乱も見られなかった．そのため，athermal Omega相は応力マルテンサイトから母相への逆変態時のバリアント選択には影響を及ぼさないことが示唆される．, 12J09335
01 Apr. 2012 - 31 Mar. 2015
