変位型相変態の新展開

1999 Fiscal Year Annual Research Report

• Project/Area Number: 09242103
• Research Institution: University of Tsukuba
• Principal Investigator: 大塚 和弘 筑波大学, 物質工学系, 教授 (50029881)
• Co-Investigator(Kenkyū-buntansha): 唯木 次男 大阪女子大学, 理学部, 教授 (90029885) ; 佐分利 敏雄 関西大学, 工学部, 教授 (40029020)
• Keywords: 変位型相変態 / マルテンサイト変態 / 変態前駆現象 / 格子欠陥 / 変態のカイネティクス / 形状記憶合金薄膜 / ナノ粒子 / 格子軟化

Research Abstract

本研究グループで行っている五つのテーマに対し、以下テーマごとに研究成果の概要を記す。
(a)2次に近い変位型相変態の研究では、Ti-Ni-Fe合金及びTi-Ni時効材の弾性定数の温度依存性を系統的に測定し、弾性定数c'と弾性異方性A=c_<44>/c'の温度依存性とR相変態の関係を明らかにした。又B2-B19変態をするTi-30Ni-20Cu合金の中性子非弾性散乱を測定し、1/2<110><11^^-0>ブリュワンゾーン境界近傍でのフォノンソフニングを見出した。
(b)変位型1次相変態と格子欠陥の相互作用に関しては、この研究で担当者等が提唱したSC-SROの存在を実験的に検証する新しい現象を見出した。即ち、逆変態後母相状態でも電顕観察でマルテンサイトのコントラストが残ることを確認すると共に、SC-SROに伴ったmicrostructure memory及び二方向形状記憶効果の現れることを見出した。
(c)変位型1次相変態の熱力学に対する新しいアプローチでは、非等温マルテンサイト変態を示すFe-32.3at.%Ni合金に静水圧を負荷すると、等温変態が起きること、さらにその圧力下で磁場を印加すると、再び非等温になることを確認した。また、Fe-Ni-Mn合金の等温変態に及ぼす定常磁場とパルス磁場の影響が異なることを見出した。
(d)薄膜における変位型1次相変態の研究では、Ti過剰Ti-Ni合金の非晶質薄膜を低温で短時間加熱して結晶化させた後、拘束時効処理を施して板状析出物を特定の面に優先析出させることにより、二方向形状記憶が発現すること、ならびその自発変形はNi過剰Ti-Ni合金薄膜におけるものの逆方向であることを見出した。
(e)Fe-Ni合金ナノ粒子の変位型1次相変態では、Fe-NiおよびAu-Cd合金ナノ粒子の変位型1次相変態について研究を行い、Fe-Ni合金ではナノ粒子は母相単結晶から単一バリアントのマルテンサイト相単結晶にBain変形することがわかった。Au-Cd合金ナノ粒子は室温以下でバルクと同様のB2-γ_2'変態を起こすこと、この場合の変態温度低下はT_0温度の低下であることを明らかにした。

Research Products

• [Publications] X.Ren et al.: "Elastic Constants of Ti_<50>Ni_<30>Cu_<20> Alloy Prior to Martensitic Transformation"Philosophical Magazine A. 79,1. 31-41 (1999)
• [Publications] J.Zhang et al.: "Elastic Constants of Ti-48 at%Fe Single Crystal Prior to B2→R Transformation"Materials Transactions,JIM. 40,5. 385-388 (1999)
• [Publications] K.Otsuka et al.: "Recent Development in the Research of Shape Memory Alloys"Intermetallics. 7. 511-528 (1999)
• [Publications] Wai Cai et al.: "Martensite Aging Effect in Ti-Pd and Ti-Pd-Ni High Temperature Shape Memory Alloys"Materials Transactions,JIM. 40,9. 895-898 (1999)
• [Publications] X.Ren et al.: "Do"Constitutional Vacancies"in Intermetallic Compounds Exist?"Scripta Meterialia. 41,9. 907-913 (1999)
• [Publications] N.Miura et al.: "Elastic Softening of Ti_<49.2>Ni_<50.8> Single Crystal Prior to B2-B19' Martensitic Transformation"Proc.of the Int.Conf. on Solid-Solid Phase Transformations '99(JIMIC-3),Japan Institute of Metals. 827-830 (1999)
• [Publications] X.Ren et al.: "Mechanism of Martensite Aging Effect and Rubber-like Behavior"Proc.of the Int.Conf.on Solid-Solid Phase Transformations '99(JIMIC-3),Japan Institute of Metals. 839-846 (1999)
• [Publications] T.Ishii et al.: "B2→γ2'+ζ2' Martensitic Transformation in Au-48.5at%Cd Alloy"Proc.of the Int.Conf.on Solid-Solid Phase Transformations '99(JIMIC-3),Japan Institute of Metals. 875-878 (1999)
• [Publications] T.Ito et al.: "Influence of Vacancies on Ageing Effect in AuCd Shape Memory Alloys"Proc.of the Int.Conf.on Solid-Solid Phase Transformations '99(JIMIC-3),Japan Institute of Metals. 879-882 (1999)
• [Publications] X.Ren et al.: "Recent Advances in Understanding the Origin of Martensite Aging Phenomena in Shape Memory Alloys"Phase Transitions. 69. 329-350 (1999)
• [Publications] K.Otsuka et al.: "Martensitic Transformations in Nonferrous Shape Memory Alloys"Materials Science & Engineering. (in press). (2000)
• [Publications] X.Ren et al.: "Understanding the Martensitic Transformations in TiNi-based Alloys by Elastic Constants Measurement"Materials Science & Engineering. (in press). (2000)
• [Publications] W.Cai et al.: "Study of R-phase Transformation in a Ti-50.7at%Ni Alloy by In-situ Transmission Electron Microscopy Observations"Materials Science & Engineering. (in press). (2000)
• [Publications] K.Otsuka et al.: "Composition Dependence of the Rubber-like Behavior in γ'_2-martensite of AuCd Alloys"Materials Science & Engineering. (in press). (2000)
• [Publications] K.Ogawa: "Bainitic Transformation of Au-47.5at%Cd Alloy"Proc.SMM'99. (in press). (2000)
• [Publications] M.Inami: "A study of Martensitic Transformation in Au-51.5at%Cd Alloy"Proc.SMM'99. (in press). (2000)
• [Publications] X.Ren et al.: "Why does the Martensitic Transformation Temperature Strongly Depend on Composition?"Proc.SMM'99. (in press). (2000)
• [Publications] Y.Murakami: "Observations of Diffuse Scattering in A Ti_<50>Ni_<48>Fe_2 Alloys by energy-filtering TEM"Proc.SMM'99. (in press). (2000)
• [Publications] X.Ren.et al.: "A Unified Model for Point-Defect Formation in B2 Intermetallic Compound's"Philo.Mag.A. (in press). (2000)
• [Publications] K.Otsuka et al.: "Martensitic Transformation and Premartensitic Phenomena in Ti-Ni-based Alloys"TMS. (in press). (2000)
• [Publications] T.Kakeshita et al.: "Effect of Magnetic Field on Athermal and Isothermal Martensitic Transformations in Fe-Ni-Cr Alloys"Materials Transactions,JIM. 40,2. 100-106 (1999)
• [Publications] T.Kakeshita et al.: "Effect of Magnetic Field and Hydostatic Pressure on the Isothermal"Materials Transactions,JIM. 40,2. 107-111 (1999)
• [Publications] T.Kakeshita et al.: "Effects of Hydrostatic Pressure and Magnetic Field on Martensitic Transformations"Proc.Int.Conf.on Solid-Solid Phase Transformations '99(JIMIC-3),Japan Institute of Metals. 907-915 (1999)
• [Publications] T.Kakeshita et al.: "Martensitic Transformations in Some Ferrous and Non-Ferrous Alloys under Magnetic Field and Hydrostatic Pressure"Phase Transitions. (in press). (2000)
• [Publications] T.Kakeshita et al.: "Kinetics of Martensitic Transformations in Some Ferrous and Non-Ferrous Alloys"Philos,Mag.B. (in press). (2000)
• [Publications] T.Kakeshita et al.: "Kinetics and Origin of Martensitic Transformations in some Ferrous and Non-Ferrous Alloys"Material Science and Engineering. (in press). (2000)
• [Publications] T.Kakeshita et al.: "Time-Dependent Nature and Origin of Displacive Transformation"Science and Technology of Advanced Materials. (in press). (2000)
• [Publications] 刑部富夫 他: "Ni過剰Ti-Niスパッタ薄膜のマルテンサイト変態と二方向形状記憶効果"日本金属学会. 61,2. 201-207 (1999)
• [Publications] A.Gyobu et al.: "Martensitic Transformation and Two-way Shape Memory Effect of Sputter-Deposited Ni-rich Ti-Ni Alloy Films"Mater.Science and Engineering A. 273-275. 749-753 (1999)
• [Publications] Y.Kawamura et al.: "Structure of Sputter-Deposited Ti-Rich Ti-Ni Alloy Films"Mater.Science Forum(Proc.of Int.Sympo.on Shape Memory Materials,held in Kanazawa). 327-328. 115-118 (1999)
• [Publications] K.Asaka et al.: "Transmission electron microscopy and electron diffraction study on structure and phase transformation of nanometre-sized Fe-15-30 at.% Ni alloy particles"J.Electron Microscopy. 48(4). 387-391 (1999)
• [Publications] K.Asaka et al.: "Martensitic transformation in nanometer-sized particles of Fe-Ni alloys"Mater.Sci.& Eng.. A275/02. 262-265 (1999)
• [Publications] K.Asaka et al.: "Facets of Nanometer-sized Fe-Ni Alloy Particles and Their Change upon the Martensitic Transformation"Proc.International Symposium and Exhibition on Shape Memory Materials(SMM-99). (in press). (1999)
• [Publications] K.Asaka et al.: "Lattice Softening and Its Relation to the Martensitic Transformation in Nanometer-sized Particles of Fe-Ni Alloys"Proc.of the Inter.Conf.on Solid-Solid Phase Transformations '99(JIMIC-3). 1068-1071 (1999)
• [Publications] Y.Nakata et al.: "High Resolution Observation of Guinier-Preston Zones in Sputter-Deposited Ti-rich Ti-Ni Films"Proc.Inter.Conf.on Solid-Solid Phase Transformations '99(JIMIC-3). 1088-1091 (1999)
• [Publications] K.Kifune et al.: "Transmission Electron Microscopy and Electron Diffraction Study of the Alloying Process of Gold-Indium Films"Proc.Inter.Conf.on Solid-Solid Phase Transformations '99(JIMIC-3). 1325-1328 (1999)
• [Publications] Y.Kubota et al.: "Charge Density Distribution of the Parent Phase of a Cu-Al-Ni Alloy by the Maximum Entropy Method"Proc.Inter.Conf.on Solid-Solid Phase Transformations '99(JIMIC-3). 871-874 (1999)