Abstract
Although the HVOF process has shown to be a technological alternative to the many conventional thermal spray processes, it would be very advantageous to design a nozzle that provides improved performance in the areas of deposition efficiency, particle in-flight oxidation, and flexibility to allow coating of ceramic powders. Based on a numerical analysis, a new nozzle was modeled, designed, tested, and used to produce thermal spray coatings according to the industrial needs mentioned above. Performance of the new nozzle was investigated by spraying several coating materials including metallic (Nickel, MCrAlY, Stainless Steel), carbide (WC-Co), and ceramic (Al2O3) powders. Particle spatial distribution, velocity, and temperature corresponding to the new nozzle and the standard HVOF gun were compared. The new nozzle provides a superior particle spatial distribution, as well as higher and more uniform particle velocity and temperature.
