Effect of Cobalt Content Gradients on Hardness of WC-Co Coatings: Finite Element Simulations

摘要

In this paper, the existing empirical models for the mechanical properties of cemented carbides are evaluated and implemented into finite element (FE) modelling using ABAQUS. The FE models are calibrated with the experimental data of cemented carbides. FE simulations of sharp indentations on WC-Co gradient coatings are made to investigate the influence of the mass cobalt content gradients on the hardness of the gradient coatings. Three cobalt content gradients with 5% Co on the coating surfaces and 13%, 21%, and 29% Co in the substrates, respectively have been considered with varied WC particle sizes and indentation penetration depths. It is shown that the composite hardness of the WC-Co gradient coatings depends on the cobalt content gradient and the WC particle size and decreases with increasing penetration depth. This decrease of the composite hardness is proportional to the cobalt content gradient while almost independent of the WC particle size.