Characterization of ZrO₂-based Coatings by Low Pressure Plasma Spraying Under Different Pressures

Low pressure plasma spray (LPPS) technology has exhibited its advantage in deposition of yttria stabilized zirconia (YSZ) coating. The YSZ coatings deposited under different chamber pressures were characterized by XRD and SEM in this paper. Preliminary results showed that as-sprayed coatings contained partially-melted zone, and increased chamber pressure was beneficial to the melting of particle. It was revealed that as-sprayed coatings were mainly composed of metastable tetragonal phase except for minor content of cubic phase analyzed by XRD. Compared to air plasma spray (APS) coating, the microhardness and toughness of well-flatten LPPS coating are respectively high and excellent.