Droplet And Particle Dynamics In Solution Precursor Plasma Spraying

The advantages of solution precursor plasma spraying in comparison to suspension plasma spraying are the use of chemical salts instead of fine particles and, a better control of coating composition and chemistry. However, the droplets undergo an additional step, i.e. solute precipitation, which may require a longer processing time. Pyrolysis and grain consolidation may, thus, not begin before droplet impact on the substrate. The optimization of the heat treatment of the liquid goes through the control of injection and, of droplet trajectory and residence time in the hotter part of the plasma. This study aims to better understand the effect of flow dynamics on solution precursor processing from in situ experimental observation of liquid evolution and, then splat observation. Shadowgraphy and particle image velocimetry are used to investigating the interaction between the liquid and cross plasma jets and determining the trajectory, size and residence time of droplets and particles.