The development of sub-surface damage during high energy solid particle erosion of a thermally sprayed WC-Co-Cr coating

Dynamic Hertzian impact theory is used to estimate the elastic contact stresses and sub-surface shear stresses induced by solid particle impacts as well as to infer likely zones of plasticity. These stress fields are related to the location of cracks and to possible mechanisms for crack propagation. The cracks appear in near-surface layers that are likely regions of localised plasticity in the matrix and could result from a mixed mode of ductile fractures driven by plastic strain accumulated after multiple solid impacts as well as fractures driven by elastic stress intensity primarily dominated by sub-surface shear stresses and surface tensile stresses.