Computer simulation of martensitic textures

摘要: We consider a Ginzburg-Landau model free energy F(ϵ, e1, e2) for (2D) martensitic transition, that provides unified understanding of varied twin/tweed textures. Here F is triple well potential in the rectangular strain (ϵ) order parameter and quadratic e12, e22 compressional shear strains, respectively. Random compositional fluctuations η(r) (e.g. an alloy) are gradient-coupled to ϵ, ~ − ∑rϵ(r)[(Δx2 Δy2)η(r)] “local-stress” model. find compatibility condition (linking tensor components ϵ(r) e1(r), e2(r)), together with local variations such as interfaces or fluctuations, can drive formation global elastic textures, through long-range anisotropic effective ϵ-ϵ interactions. have carried out extensive relaxational computer simulations using time-dependent (TDGL) equation supports our analytic work shows spontaneous parallel twins, chequer-board tweed. The observed microstructure NiAl FexPd1 x alloys be explained on basis analysis simulations.