Numerical and experimental investigations of splat geometric characteristics during oblique impact of plasma spraying

Splats are obtained on the substrates inclined at different angles (0°, 20°, 40° and 60°) by plasma spraying process and characterized by SEM and WYKO® optical surface profiler. Numerical model is developed using CFD software FLOW-3D® to simulate the process of droplet impact, spreading and solidification onto the substrates. Splat characteristics such as spread factor, aspect ratio and fractional factor are defined and compared between simulation and experiment. Fair agreements are obtained. In addition, the impacting behavior including spreading and solidification are analyzed in details from the simulation results. The rates of reduction in droplet kinetic energy during impact, spreading and solidification are also compared between different inclination angles.

► Time history of droplet evolution has been carried out via CFD software FLOW-3D®. ► Splats are obtained experimentally and characterized by SEM and WYKO® optical surface profiler. ► Experiments and simulations are conducted for four substrate inclination angles and fair agreements are obtained. ► Simulation provides more insights into the dynamics of droplet impact. ► Simulation shows that droplet spreading is completed earlier than solidification.