Ni_（47）Ti_（44）Nb_9合金热诱发马氏体相变研究

Study on Thermally-Induced Martensitic Transformation in Ni_(47)Ti_(44)Nb_9 Alloy

采用电阻法，Ｘ射线衍射及ＴＥＭ技术研究了Ｎｉ４７Ｔｉ４４Ｎｂ９形状记忆合金的相组成及热诱发马氏体相变．结果表明，Ｎｉ４７Ｔｉ４４Ｎｂ９合金室温下由ＴｉＮｉ基体相和β－Ｎｂ相组成；当试样温度降低到Ｍｓ点以下时，具有Ｂ１９＇单斜结构的热诱发马氏体呈群团式生长，形成由二至三个取向的孪晶微区组成的群团状马氏体．

The constitutional phases and thermally-induced martensitic transformation were studied in the Ni47Ti44Nb9 shape-memory alloy by means of the electrical resistance method, X-ray diffraction and TEM.The results showed that there exist two constitutional phase:TiNi matrix and β-Nb phase in the alloy,and the thermal-induced martensite with B19' monoclinic structure is growing in a cluster form when the specimen is cooled below Ms, thus forming the cluster-shaped martensite which generally consists of small twinning domains with two or three different orientations.