Representative volume element (RVE) based crystal plasticity study of void growth on phase boundary in titanium alloys

Abstract

Crystal plasticity based finite element method (CPFEM) studies have been successfully used to model different material behaviour and phenomenon, including but not limited to; fatigue, creep and texture evolution. This capability can be extended to include the ductile damage and failure in the model. Ductile failure in metals is governed by void nucleation, growth, and coalescence. High strength titanium alloys can be formed from sheets and components and are prone to ductile failure. α – β Titanium alloys are in widespread use, ranging from aerospace, automotive, energy to oil and gas. They have multiple phases present in the microstructure but α and β phases are dominant and are present in various morphologies. This study focuses on the 3D representative volume element (RVE) simulations of spherical void of known initial porosity at the interface of α and β phase single crystals. The effect of initial porosity, applied triaxiality and orientation of RVE with respect to the loading direction is investigated. Slip based crystal plasticity formulation implemented as a user subroutine in commercially available software was used to simulate the void growth and the results of the same are presented. Lastly, a generalised correlation among loading type, loading direction, crystal orientation, phase interface orientation, and void growth is presented.