CoNiZ系列合金的结构和马氏体相变性质  

Structure and martensitic transformation of the CoNiZ alloys

作　　者：代学芳[1] 刘何燕[2] 闫丽琴[2] 曲静萍[2] 李养贤[2] 陈京兰[1] 吴光恒[1] 

机构地区：[1]中国科学院物理研究所北京凝聚态物理国家实验室,北京100080 [2]河北工业大学材料学院,天津300130

出　　处：《物理学报》2006年第5期2534-2538,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50471056);河北省自然科学基金(批准号:503031)资助的课题~~

摘　　要：利用X射线衍射研究了CoNiZ(Z=Si,Sb,Sn,Ga等)合金在不同热处理条件下的相组成.当Z元素为Sn,Sb时,材料是完全的B2结构;但Z为Si时,材料变成面心立方的γ相.形成B2还是γ相由电子浓度和原子尺寸效应两种因素共同决定.而CoNiGa的研究结果表明,在合金中除了形成B2结构的同时还容易形成γ相,常表现出两相共存的特性.对材料进行不同方式的热处理可以使合金中两相的含量有所消长,γ相含量的多少对CoNiGa合金的马氏体相变有很大的影响.分析指出,两相共存及其所带来的物性变化是CoNiGa铁磁性形状记忆合金非常有利用价值的物理性质.Structures of CoNiZ （ Z = Si, Sn, Sb, Ga） alloys have been investigated. We found that CoNiZ alloys have B2 structure with Z = Sn or Sb, but when Z = Si, the structure is fcc γ phase. When B2 structure coexists with γ phase in CoNiGa alloys, γ phase affects the temperature of martensitic transformation greatly. The structure of the alloy is determined by beth the electron concentration and the size effect. The coexistence of two phases in the CoNiGa alloys can be changed by various heat treatment conditions. These results indicate that the martensitic transformation behaviors can be adjusted just by heat treatments, other than by modifying the composition as being done conventionally for other ferromagnetic shape memory materials.

关 键 词：HEUSLER合金 马氏体相变 Γ相 

分 类 号：O482.523[理学—固体物理]