航空发动机涡轮叶片工作时表面经常产生CaO-MgO-Al2O3-SiO2(简称CMAS)等沉积物。本文中研究了电子束物理气相沉积(EB-PVD)制备ZrO2热障涂层(TBCs)在CMAS环境下的热循环行为及失效机制。结果表明, 在1200℃热冲击条件下, 表面涂覆CMAS的热障涂层的热循环寿命低于100次, 而未涂覆CMAS的涂层寿命达到500次以上, CMAS 的存在加速了热障涂层的剥落失效。在1200℃经过210次循环后, ZrO2陶瓷层与CMAS之间形成了约8 μm厚的互反应区, 其形成主要与CMAS中Ca^2+内扩散有关。CMAS环境下热障涂层陶瓷层产生大量横向裂纹, 涂层的失效主要以陶瓷层片状剥落为主。
CaO-MgO-Al2O3-SiO2 (CMAS in short) deposits are often generated on the surface of in-service aircraft engine blades. In this paper, the thermal cycling behavior and associated failure mechanism of EB-PVD zirconia-based thermal barrier coatings (TBCs) with CMAS deposits were investigated. The results show that the thermal cycling life of TBCs with CMAS deposits at 1200℃ is less than 100 cycles, whereas the life of TBCs without CMAS is more than 500 cycles. CMAS deposits accelerate the spallation failure of TBCs. After 210 thermal cycles at 1200℃, about 8 μm interaction layer is formed between CMAS and zirconia ceramic layer, which is mainly due to the inward diffusion of Ca^2+ from the CMAS deposits. A large number of transverse cracks are generated in the ceramic layer of TBCs with CMAS deposits. The failure of TBCs occurs mainly by chipping spallation of the ceramic layer.