Microstructural Evolution of Plastic Deformation of NiTi Shape Memory Alloy at Low Temperature  

作　　者：张艳秋 江树勇 ZHAO Yanan TANG Ming 

机构地区：[1]Industrial Training Centre,Harbin Engineering University

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2013年第5期1034-1037,共4页武汉理工大学学报（材料科学英文版）

基　　金：Funded by National Natural Science Foundation of China(No.51071056);the Fundamental Research Funds for the Central Universities of China(Nos.HEUCF121712 and HEUCF201317002)

摘　　要：Nickel-titanium shape memory alloy （NiTi SMA） which possesses crystal structure of B2 austenite at room temperature was subjected to plastic deformation at low temperature （-150 ℃） by means of local canning compression. The microstructural evolution of NiTi SMA at the different deformation degree was investigated by transmission electron microscopy （TEM） and high resolution transmission electron microscopy （HRTEM）. At the deformation degree by 15%, a high density of dislocations occurs in the deformed NiTi sample. At the deformation degree by 25%, the deformed NiTi sample exhibits the martensite morphology due to the pinning of dislocations at the grain boundaries. At the deformation degree by 50%, a small amount of nanocrystalline phase arises in the deformed NiTi sample. At the deformation degree by 80%, severe plastic deformation （SPD） leads to the occurrence of a great deal of amorphous and nanocrystalline phase,Nickel-titanium shape memory alloy （NiTi SMA） which possesses crystal structure of B2 austenite at room temperature was subjected to plastic deformation at low temperature （-150 ℃） by means of local canning compression. The microstructural evolution of NiTi SMA at the different deformation degree was investigated by transmission electron microscopy （TEM） and high resolution transmission electron microscopy （HRTEM）. At the deformation degree by 15%, a high density of dislocations occurs in the deformed NiTi sample. At the deformation degree by 25%, the deformed NiTi sample exhibits the martensite morphology due to the pinning of dislocations at the grain boundaries. At the deformation degree by 50%, a small amount of nanocrystalline phase arises in the deformed NiTi sample. At the deformation degree by 80%, severe plastic deformation （SPD） leads to the occurrence of a great deal of amorphous and nanocrystalline phase,

关 键 词：NiTi alloy severe plastic deformation shape memory alloy amorphization NANOCRYSTALLIZATION 

分 类 号：TG139.6[一般工业技术—材料科学与工程] TG301[金属学及工艺—合金]