Characterization of Thermal Property of YSZ Coatings Deposited by Suspension Vacuum Plasma Spraying

As the turbine inlet temperature increases for enhancing of efficiency of gas turbine engine, the importance of thermal barrier coatings(TBC) is also increasing. In order to improve the performance of thermal barrier coatings, suspension plasma spraying(SPS) is replacing atmospheric plasma spraying(APS) for formation of the YSZ top coating. SPS enables to feed submicron or nano-sized particles into the plasma flame and it causes the unique structural, mechanical, thermal properties of coating. However, suspension atmospheric plasma spraying takes too long to form proper thickness. In this research, various YSZ coatings were obtained by suspension vacuum plasma spraying(SVPS) on NiCoCrAlY bond coated Ni base superalloy substrates. Microstructures of YSZ coatings were characterized by SEM on each spray conditions. Formation rates of SVPS YSZ coatings showed higher than that of SAPS YSZ coatings. Thermal cyclic lifetimes at 1100 ^oC were evaluated for each SPS YSZ coatings.