Fracture modelling of WC-Co hardmetals using crystal plasticity theory andthe Gurson model

The behaviour of edge cracks under Mode I loading in the SVC-Co material sy stem is studied using the finite element method (FEM). This work focuses on ductile failure mechanisms in the Co binder. A micromechanical approach is taken whereby Co layers are modelled explicitly. An embedding technique is employed. Crystal plasticity theory and J(2) Bow theory are used to repres ent plastic deformation in Co ligaments. Areas of high hydrostatic stress, triaxiality and accumulated slip or effective plastic strain are identified within the binder material. The Gurson model is used to model crack growth in the Co ligaments. Fracture resistance curves are obtained giving a rela tionship between macroscopic material behaviour and microscopic failure mec hanisms. Factors effecting the crack growth in single and multiple ligament s are identified.