Residual Stress Distribution Through the Thickness of WC-10Co-4Cr Coating Deposited by HVOF: Experimental and Simulation Study

摘要

Utilization of WC-10Co-4Cr coating, sprayed by High-Velocity Oxygen Fuel, has significantly expanded due to its high corrosion and wear resistance. In this study, the in-plane residual stresses in the coating were determined experimentally with the x-ray diffraction technique, using the sin(2)psi method and compared to finite element analysis (FEA). The chemical layer removal process was used to determine the residual stress experimentally, through the thickness of the coating. In the FEA, the effect of impingement of a WC-10Co-4Cr particle on the substrate was first studied and the results of impingement analysis were used as input data in a thermomechanical model of the coating process. Experimental results, in agreement with simulation studies, showed that the inplane surface residual stresses in the WC-10Co-4Cr coating were compressive. The magnitude of this compressive stress increased with depth, relative to the free surface of the coating. The largest compressive residual stress was measured at the coating-substrate interface. Simulation results predicted that the stress distribution through the coating was uniform, except at the edges of the sample, where tensile stress concentrations existed at the coating-substrate interface. This region is thus prone to cracks and delamination of the coating.