Model of the Thermal Physics in Plasma-Sprayed Coatings and Calculation of Residual Stress

Residual internal stresses are induced in thermal-spray coating during deposition, owing to the different thermophysical properties between substrate and coating as well as different spraying parameters. In this paper, based on analysis of particle's deposition process, the thermal physics model of temperature field during the plasma spraying processes are established. Spraying process parameters and mechanical and thermal properties of sprayed materials were considered in this model. Regarding the formation of coating as superimposed n sub - coatings with thickness h(min), the temperature change can be described in a two-stage calculation model. At the initial stage, temperature does not exceed 20% corresponding spraying material melting point. At the final stage substrate, the coating and the substrate were bound and led to the formation of residual stress at the moment when system achieved the highest temperature.: This model has made it possible to evaluating the components of residual stresses.