Abstract
As a new processing technology, plasma spray physical vapor deposition (PS-PVD) is capable to deposit coatings out of the vapor phase with high deposition rate. Moreover, the resulting quasi-columnar coatings were unique, hardly deposited by other process. Due to its low thermal conductivity and excellent superior strain tolerance, quasi-columnar coatings attract much attention in the thermal barrier coatings (TBCs) field. In this paper, the morphology variation of the quasi-columnar yttria stabilized zirconia (YSZ) coatings deposited under different conditions was investigated. Combined the morphology of the initial deposits during short time spraying, the deposition mechanism of quasi-column microstructure was concluded. It can be found that the quasi-column coating was formed by co-deposition of vapor phases and solid particles. The vapor phase can develop into column, while the solid particles not only intensified the shadowing effect but also destroyed the nucleus during vapor deposition.
