FEM simulation of void coalescence in FCC crystals

Abstract

To investigate the coalescence behaviors of voids in FCC crystals, three bicrystal models were used to study the coalescence of voids in single crystals, voids at grain boundary and voids in two grains by using three-dimensional crystal plasticity finite element method, which was implemented with rate dependent crystal plasticity theory as user material subroutine. By comparison the width of inter-void ligament in bicrystals, significant effects of orientation factor and high-angle grain boundary on void coalescence were revealed: (1) Voids in soft orientation grains tend to coalesce much easier than that in hard orientation under the strain controlled boundary condition. (2) For void coalescence at grain boundary, with the orientation factor’s difference between the two grains increasing, larger deformation mismatch is induced between grains, and the void prefers to grow along grain boundary. (3) Large orientation factor’s difference accelerate void coalescence at grain boundary, but decelerate void coalescence between grains.