Simulation of PFZ on intergranular fracture based on XFEM and CPFEM

Abstract

A unit cell including the matrix, precipitation free zone (PFZ) and grain boundary was prepared, and the crystal plasticity finite element method (CPFEM) and extended finite element method (XFEM) were used to simulate the propagation of cracks at grain boundary. Simulation results show that the crystallographic orientation of PFZ has significant influence on crack propagation, which includes the crack growth direction and crack growth velocity. The fracture strain of soft orientation is larger than that of hard orientation due to the role of reducing the stress intensity at grain boundary in intergranular brittle fracture. But in intergranular ductile fracture, the fracture strain of soft orientation may be smaller than that of hard orientation due to the roles of deformation localization.

Keywords

precipitation free zone (PFZ) / intergranular fracture / grain boundary / extended finite element method (XFEM) / crystal plasticity

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