Mechanics of materials undergoing martensitic phase change: A micro-macro approach for transformation induced plasticity

摘要

A micromechanical model is developed to predict the overall behavior of a Representative Volume Element (RVE) of a material undergoing nonthermoelastic martensitic phase transformation. The theoretical approach is based on the evaluation of the energy dissipation using the concept of moving boundaries. Assuming an ellipsoidal growing of martensitic microdomains and taking into account some physical aspects typical of martensitic phase transformation in ductile materials, the obtained dissipation is reduced to a more simple form leading to choose the volume fractions of each possible martensitic variants as the internal variables describing the microstructure evolution. The nucleation and growth conditions of a martensitic microdomain are derived using simultaneously the classical inelastic inclusion problem together with interface operators. More explicit relations are developed in the case of a simple shear test where different growing modes of a martensitic microdomain are discussed. The obtained results are combined with kinetics and kinematics studies to derive the constitutive equation of an austenitic single crystal from which the overall behavior of a polycrystalline RVE is deduced using the self-consistent scale transition method. Comparison with experimental data shows a good agreement. [References: 34]