Investigation for Plasma Spray with Internal Powder Feed

Plasma spraying with powder injecting inside nozzle can be deemed to enhance deposition efficiency and reduce power consumed markedly compared to injecting powders at the nozzle exit most general particle injecting method. However powder injecting inside nozzle also encounters a problem from the powder deposition on the nozzle and to clog particles channels. In this study Al₂O₃-40TiO₂ powders with a mean diameter of 20 micrometer were used to deposit coatings which powder injected inside nozzle. The effect of powder feed rate and plasma power supply and gases composition of plasma on the deposition efficiency and particles clogging on the anode nozzle were investigated. The results show that with decreasing powder feed and increasing velocity of plasma jet would avoid particles clogging on the nozzles.