Investigations of the Dynamics of Twinned Microstructures and the Formation of Martensite

本工作研究了具有工程意义的晶体合金中动态孪晶生长和相界演化的微观力学。孪生的研究是理解马氏体相变和形状记忆效应的先决条件。一般的方法是基于现代相变材料的非线性弹性动力学理论。一个重要的因素将是本构律的选择，即应变能函数，它具有许多局部最小值（势井）作为应变的函数，并表现出适当的各向异性类型。将阐述和分析一类涉及孪晶区向非孪晶快速扩展的动态问题。＊＊＊

9312858 Rosakis This work studies the micromechanics of dynamic twin growth and the evolution of phase boundaries in crystalline alloys of engineering importance. The study of twinning is a prerequisite to the understanding of martensitic transformations and of the shape- memory effect. The general method of approach is base don the modern theory of nonlinear elastodynamics of materials that change phase. An important ingredient will be the choice of a constitutive law, namely a strain energy function which has many local minima (potential wells) as a function of strain and exhibits and appropriate type of anisotropy. A class of dynamic problems involving rapid propagation of twinned zones into untwinned crystals will be formulated and analyzed. ***