Structural, Mechanical and Erosion Properties of Plasma Sprayed Yttrium Oxide Coatings by Axial Injection of Fine Powder Slurries for Semiconductor and Flat-Panel-Display Applications

In this study, high-power axial-injection suspension plasma spraying is used to synthesize yttrium oxide coatings from fine powder slurries. The coatings are assessed based on microstructure, hardness, and porosity and compared with coatings produced by other spraying methods. Resistance to erosion from CF₄ containing plasma is also investigated. Test results show that the suspension plasma sprayed Y₂O₃ coatings are superior in terms of density, hardness, uniformity, and plasma erosion resistance. They also retain a smoother surface when exposed to plasma that contains CF₄.