Computational analysis of the influence of Ar/H2 and arc current on the in-flight particle in plasma spraying

Plasma spraying is extensively used for the deposition of any material, including metal and ceramics, owing to its high thermal energy. Various process parameters are required from the plasma torch to the substrate for the deposition of coatings. The correlation between process parameters and properties of in-flight particles is not well understood due to the complexity and number of process parameters. Specifically, arc current and gas mixtures significantly impact both heat and momentum transfer of the plasma jet to the particles. In the present study, computational simulation was used to predict the behavior of Al2O3 and MgAl2O4 particles under process conditions such as arc current and gas mixtures. The simulation results of the plasma jet using thermal plasma modeling were coupled with discrete phase modeling to predict in-flight particle behavior. The temperature and velocity of the plasma jet and particles were calculated for various arc currents and Ar/H2 flow rates. Also, the temperature and velocity of the in-flight particles were compared to experimental data. The relationship between the plasma jet and in-flight particles was investigated using a simulation model combined with the thermophysical properties of gas mixtures.