Ginzburg-Landau Modeling for Martensitic Transformation Coupled with Composition Redistribution

Abstract

The Ginzburg-Landau (G-L) model possesses the thermodynamic foundation of energy minimization and is available for many dynamic formalisms, thus holds great potential for investigating the complex materials behaviors. The common ingredient in energy spawns the real-time control of diffusion potential and chemical mobility by integrating G-L model with CALPHAD technique. The coupling between martensitic transformation and dislocation evolution is achieved by mean of continuous mechanism. The updated G-L model is then validated against the martensitic transformation coupled with composition redistribution in Fe-C binary system. The modeling allows some deeper insights into the mechanisms of coupling effects behind the observed phenomena. It has been proven that the partitioning of carbon in steels is an ordinary diffusion governed by instantaneous diffusion potential and chemical mobility. The rough twin boundaries and retained austenite within the martensite should be attributed to the effect of dislocations. Although the developed model in this chapter has deficiencies, it sheds some lights on the integration of multi-physics models for a complex phase transformation.