Numerical Modeling of Transient Temperature and Stress in WC–10Co4Cr Coating During High-Speed Grinding

Abstract

Based on the classical theory of heat conduction and thermoplastic mechanics, the three-dimensional heat transfer and thermal stress models of high-velocity oxygen fuel WC–10Co4Cr coating under the action of a moving heat source during grinding were developed. Considering temperature-dependent material properties, the transient temperature field and the thermal stress field generated in workpiece were simulated by a finite element method (FEM). As both the thermal conductivity and the specific heat capacity of WC–10Co4Cr are larger than 300 M, temperature rise mainly occurred in the coating. The rise in grinding temperature was discontinuous along the depth of the workpiece, and the temperature gradient at the coating–substrate interface was found to be the largest. Due to the large difference in thermal expansion coefficient between coating and substrate material, considerable thermal stress was generated at the bonding surface. Grinding temperature and thermal stresses at the coating–substrate interface started to increase with the decrease in coating thickness. Grinding surface temperatures were measured experimentally for different coating thicknesses, and simulation results were compared with the obtained experimental values. It was found that FEM results were well consistent with experimental observations.