Effect of Air Plasma Spraying Parameters on the Quality of Coating

Abstract

In this study, air plasma spraying (APS) has been used to produce a cermet’s composite coating based on powder of ceramic oxides (Al₂O₃-3%wtTiO₂) reinforced by mineral powders as bonding material (Ni-20%wtCr6Al) at different rates onto AISI 304 stainless steel substrates. Coating deposition by plasma spraying involves a number of process variables such as powder flow rate, electric current and standoff-distance., which participate in a large way to the best quality of the coating. The obtained results showed that a higher spraying power and a shorter spraying distance result in the higher deposition efficiency, the better microstructure and the higher micro-hardness for the coating. It is concluded that the spraying power and distance are important factors influencing the deposition efficiency, microstructure and micro-hardness of the plasma sprayed (Al₂O₃-3% wt TiO₂) coating.