铁磁形状记忆合金Ni-Mn-Ga单晶的马氏体孪晶再取向应力应变行为  

MARTENSITIC TWINS REORIENTATION AND STRESSSTRAIN BEHAVIOR OF FERROMAGNETIC SHAPE MEMORY ALLOYS Ni-Mn-Ga SINGLE CRYSTALS

作　　者：邓丽芬[1] 李岩[1] 蒋成保[1] 徐惠彬[1] 

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100083

出　　处：《金属学报》2004年第12期1290-1294,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金资助项目50271002;50131010

摘　　要：采用定向凝固区熔法制备了铁磁形状记忆合金Ni53Mn23.5Ga23.5,Ni54Mn23Ga23和Ni50Mn27Ga23晶体.用线切割切取5 mm×5 mm×6 mm的长方体单晶,X射线极图法测定单晶体的生长方向与[100]方向相差小于5°.沿单晶试样的3个边分别进行压缩实验,研究马氏体孪晶再取向应力应变行为.结果表明,沿单晶生长方向为孪晶再取向最有利方向,孪晶再取向应力最小,仅为3-7 MPa.压缩能有效地提高马氏体变体的有序化和择优化,形成近单变体状态.Ferromagnetic shape memory alloys Ni53Mn23.5Ga23.5, Ni54Mn23Ga23 and Ni50Mn27Ga23 single crystals were prepared by zone-melting unidirectional solidification. The orientations of the cut single crystals were determined by X-ray diffraction method. The Ni-Mn-Ga crystal growth direction is along [100] with the deviation less than 5degrees. The martensitic twins reorientation process was detected by the stress-strain curves. The compression experiments along different directions were performed, respectively. The results show that the compression improves the texture of favorable martensitic variants and turns them into a single martensitic variant by martensite reorientation.

关 键 词：形状记忆合金 NI-MN-GA 马氏体孪晶 应力-应变 

分 类 号：TG139.6[一般工业技术—材料科学与工程]