An Integrated Mathematical Model of the Plasma Spraying Process

This paper describes an integrated mathematical model of the atmospheric pressure plasma spray process and presents a comparison between computed results and experimental measurements. The model describes fluid flow and heat transfer in the plasma plume; heating, melting and vaporization of injected powder particles; deposition and freezing of the molten particles; and the transient thermal history of the substrate. The plasma plume calculations are based on the solution of the two-dimensional turbulent equations of motion. A dynamic and thermal balance permits the calculation of the particle temperatures and velocities. The thermal history of the growing coating is calculated under typical cyclic spraying conditions. The computed results are compared against existing experimental data obtained from commercial plasma spraying torches.