马氏体相变晶体学概述(一)

An Outline of Crystallography of Martensitic Transformation(Ⅰ)

阐明马氏体相变的惯习面、位向关系和亚结构等晶体学特征是马氏体相变研究的重要内容之一。金属材料马氏体相变的位向关系有K-S关系、N(或N-W)关系,G-T关系和Burgers关系等,相应的经典切变模型为K-S模型、N模型、G-T模型和Burgers模型。但这些模型均不能解释相变的表面浮凸和惯习面问题。以不变平面应变为基础的马氏体相变晶体学表象理论,即P1=RBP或P1P2=RB,能成功预测许多马氏体相变的晶体学特征。其不变线S的获得和求取是表象理论的关键,通过S的逆分解可以求解相变的惯习面和位向关系,结果与实验测定值相吻合。然而,应用上述理论求解板条马氏体和(225)f马氏体的晶体学特征的努力并不成功。近二三十年来,发展了晶体学理论的双点阵不变切变模型,F=RPS2S1。由此出发,能够说明板条马氏体和(225)f马氏体的晶体学特征。此外,简单介绍张文征等学者的一些马氏体相变晶体学方面的研究成果。

It is an important research subject to shed light on crystallographic features of martensitic transformation, such as habit plane, orientation relationship, substructure and so on. Several main orientation relationships for the martensitic transformation of metal materials are K-S relationship, N （ or N-W） relationship, G-T relationship and Burgers relationship. Correspondingly, four classical shear models are K-S model, N model, G-T model and Burgers model. But, these models are failure to explain the problems involving surface relief and habit plane of the transformations. The phenomenological theory based on the invariant plane strain （ IPS）, i.e. P1 = RBP or P1P2 = RB, have been successful in predicting the crystallographic features of many martensite transformations. The calculation of invariant line S is an key to phenomenological theory. The orientation relationship and habit plane can be calculated though anti-decomposition of S, and the obtained results are consistent with the experimental results. However, none of the attempts to interpret the crystallographic characteristics of lath martensite and （225）f martensite using the above phenomenological theory is successful. In the last twenty odd years, the double lattice invariant shear version of phenomenological theory,which can be represented by F = RBS2S~ , has been created and can explaine the known crystallographic features of the lath martensite and （225）f martensite. Moreover, achievements in research on the crystallography of martensite phase transformations of ZHANG Wen-zhen and her co-workers were introduced briefly.