Characterization of Ultra High Temperature Ceramic Coatings Deposited by Vacuum Plasma Spraying

摘要

1. TaC coatings with TaO and Ta_2C were deposited by VPS 2. Enough carrier gas flow was key parameter for reducing oxidation of TaC. 3. Deposition TaC coating at low working pressure decreased carbon loss and made flatter splats. 4. HfC coatings with various phases of HfO_2 were deposited by VPS. 5. Coatings deposited at low working pressure showed lower oxide content. 6. More oxide content in HfC coatings deposited when spraying distance is shorter than significant distance. 7. TaC coatings showed that easier to oxidize than HfC coatings. 8. Deposition rates of TaC coatings were higher than those of HfC coatings. 9. TaC coatings showed more porous microstructure than HfC coatings.