马氏体相变的一维金兹堡-朗道理论

One-Dimensional Ginzburg-Landau Theory for Martensitic Transformation

改进了 Falk提出的马氏体相变的一维金兹堡 -朗道理论 ,在体系自由能中加入了马氏体周围母相的应变能 ,由此推出了一个 4阶金兹堡方程 ,其中有约化温度 t与约化母相弹性模量 p两个重要参数 .方程的两类解分别代表表面马氏体和孪晶马氏体的形核 .两种马氏体的形成与参数 t和p密切相关 :当固定 p而降低 t时 ,表面马氏体将先于孪晶马氏体出现 ;当固定 t而增加 p时 ,孪晶马氏体形成的起始温度下降 .按此修正 G- L理论所得到的解比 Falk的解更符合实际马氏体相变的形核过程 .

A modified one-dimensional Ginzburg-Landau (G-L) theory for martensitic transformation is proposed on that basis of that developed by Falk. The strain energy of the parent phase surrounding the martensite is added to free energy and a fourth order Ginzburg equation was derived. There are two important parameters is this equation, namely, t, the reduced temperature and p, the reduced elastic modulus of the parent phase. Two kinds of solutions are obtained, which represent the nucleation of surface and twin martensites respectively. The formation of the surface or twin martensite is closely related to t and p. By fixing p and decreasing t, the solutions indicate that the surface martensite appears before the twin martensite. While fixing t and increasing p, the temperature at which the twin martensite starts to appear is lowered. The solutions derived from this modified G-L theory show a better consistency with the practical process of martensitic nucleation than those obtained by Falk.