Crystal plasticity analysis based on the TWIP model considering a flow stress which depends on the volume fraction of twin phase

Abstract

Recently, TWIP steels have been focused on because of their excellent ductility and strength. One approach to formulating the behavior of materials containing deformation twins in terms of crystal plasticity is a model in which each material point in the material is represented by a mixture law based on the volume fractions of the twin and matrix phase. Such kind of approach cannot express the macroscopic mechanical property more precisely because the influence of twin boundaries is neglected. In this study, the mechanical property under the existence of twin boundaries is researched by using crystal plasticity simulation. The analysis intended for a material with a laminar structure made of twin phase and matrix phase reproduces the accumulation of dislocations at twin boundaries. By investigating the influence of twin boundaries on several models with different volume fractions of each phase, the relationship between the volume fractions of the twin phase and the influence of twin boundaries was determined.