Laser Measurement of Particle Velocities in Vacuum Plasma Spray Deposition

摘要

The velocity of spray particles in vacuum plasma spray deposition affects particle residence time in the plasma, heat transfer from the plasma to the particles, and the kinetic energy upon impact with the target surface. Hence, particle velocity is an important process variable which influences particle melting as well as the density and adhesion of the deposited material. A laser velocimeter system has been used to investigate the effects of variations in process parameters on particle velocities in a vacuum plasma spray system. The results reveal significant relationships between particle velocity and process parameters such as spray particle size, particle mass density, spray chamber pressure, plasma arc power, and electrode geometry. Conversely, over the range of conditions studied, particle velocity was relatively insensitive to changes in plasma gas supply rate, plasma gas composition, and power feed rate. 6 figs. (ERA citation 13:030562)