FEM analysis on the effect of cobalt content on thermal residual stress in polycrystalline diamond compact (PDC)

Abstract

Thermal residual stress in Polycrystalline Diamond Compacts (PDCs) is mainly caused by the mismatch in the Coefficients of Thermal Expansion (CTE) between the polycrystalline diamond (PCD) layer and WC-Co substrate. In the PCD layer, the CTE of cobalt exhibit magnitudes four times larger than those of diamond. Cobalt content in the PCD layer has important effects on the thermal residual stress of PDCs. In this work, the effects of cobalt content on thermal residual stress in PCDs were investigated by the Finite Element Method (FEM). The simulation results show that the thermal residual stress decreases firstly, and then increases with increasing cobalt content (1 vol.%–20 vol.%), which reaches a minimum value when the cobalt content is about 10 vol.%. The FEM analysis results are in agreement with our experimental results. It will provide an effective method for further designing and optimizing PDC properties.