CMAS环境下电子束物理气相沉积热障涂层的热循环行为及失效机制  

Thermal cycling behavior and associated failure mechanism of EB-PVD thermal barrier coatings with CMAS deposits

作　　者：苗文辉[1] 王璐[2] 郭洪波[1] 彭徽[1] 王凯[1] 宫声凯[1] 

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100191 [2]中航工业沈阳黎明航空发动机(集团)有限责任公司,沈阳110043

出　　处：《复合材料学报》2012年第5期76-82,共7页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(50771009;51071013);国家重点基础研究发展计划(2010CB631200)

摘　　要：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8μm厚的互反应区,其形成主要与CMAS中Ca2+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.

关 键 词：热障涂层 循环热冲击 CMAS 互反应区 失效 

分 类 号：TB332[一般工业技术—材料科学与工程] V254[航空宇航科学与技术—航空宇航制造工程]