Numerical Investigation of the Influence of Injection Modes in the Solution Precursor Plasma Spraying

Solution precursor plasma spraying has been used to produce finely structured ceramic coatings with nano- and sub-micrometric features. The solution is injected into the plasma jet either as a liquid stream or gas atomized droplets. Then the solvent vaporizes very fast as the droplets travel downstream. Solid particles are finally formed, and the particle are heated up and accelerated to the substrate to generate the coating. The properties of coatings obtained are extremely sensitive to the process parameters, such as the torch operating conditions, the injection modes of the solution, and the injection parameters. This paper numerically investigates the effect of the two injection modes on the size distribution of injected droplets. The particle/droplet size, velocity, temperature and position distribution on the substrate are predicted for different injection modes. The effect of injection parameters, such as injection velocity, injection angle, and injection position, are also studied.