Erosion Behavior of PS-PVD Thermal Barrier Coatings and the Effect of Composite Coating (PS-PVD + APS) Thickness

Abstract

In this work, feather-column 7YSZ thermal barrier coatings (TBCs) were prepared by plasma spray-physical vapor deposition (PS-PVD). The anti-particle erosion test was carried out at room temperature to study the erosion behavior and failure mechanism of PS-PVD TBCs. The results showed that the particle erosion process of the PS-PVD TBCs experienced three stages of high-rate, medium-rate and slow-rate erosion. In order to improve the particle erosion resistance of the PS-PVD TBCs, different thicknesses of dense-layered coatings were prepared on the surface of the PS-PVD TBCs by air plasma spraying (APS). The effect of dense-layered thickness on the erosion behaviour of PS-PVD TBCs was discussed. Experimental results showed that, as the thickness of the dense-layered increased, the erosion resistance of the PS-PVD TBCs enhanced. When the thickness of the dense-layered coating was 5μm, it was not obvious upon the influence on the erosion failure behavior of the PS-PVD TBCs. In the case of a 10μm dense-layered coating, the erosion resistance performance of the PS-PVD TBCs improved by about 30%. While the erosion resistance performance of the PS-PVD TBCs increased almost 4 times when the thickness of the dense layer reached 20μm.