Modelling of the plasma-substrate interaction and prediction of substrate temperature during the plasma heating

. Temperature of the substrate during plasma heating and spraying plays an important role on quality of the substrate and coating. In this study a three dimensional numerical model is developed to simulate the Ar-N 2 plasma jet and conjugate heat transfer between plasma and substrate. The influencing of operating parameters on thermal flux from the plasma to the substrate and substrate temperature are discussed. Transient simulations are carried out to predict the substrate temperature with heating time. The arc current, gas flow rate, stand-off distance, substrate material and environment around the substrate significantly affect the thermal flux to the substrate. Heat flux to the substrate cannot be neglected in the coating built-up models. Present model is validated by comparing the results of present model with previous predictions and measurements.