循环热载荷下CMAS侵蚀对EB-PVD热障涂层微裂纹特性的影响  

Effect of CMAS Infiltration on the Microcrack Characteristics of EB-PVD Thermal Barrier Coating under Cycle Thermal Loading

作　　者：王婕 WANG Jie(Aero Engine Academy of China,Beijing 100097,China)

机构地区：[1]中国航空发动机研究院,北京100097

出　　处：《航空发动机》2020年第4期92-97,共6页Aeroengine

基　　金：航空动力基础研究项目资助。

摘　　要：为考察钙镁铝硅酸盐(Calcium-Magnesium-Alumino-Silicate,CMAS)侵蚀对柱状晶间微裂纹附近温度场、应力场以及能量释放率的影响规律,建立含微裂纹的电子束物理气相沉积(Electron Beam-Physical Vapor Deposition,EB-PVD)热障涂层数值模型。分析了材料常数、裂纹角度及裂纹长度对微裂纹尖端场的影响,详细讨论了循环热载荷下CMAS对微裂纹特性的影响规律,获得了CMAS侵蚀对应力场分布影响的3个不同阶段。结果表明:裂纹尖端应力随CMAS侵蚀深度和涂层间热失配的增加而显著增大;随着CMAS侵蚀时间的延长,涂层的隔热性能降低,裂纹尖端应力显著增大,易造成涂层的分层剥落失效;随着CMAS侵蚀深度的增加,裂纹尖端温度场和应力场以及能量释放率明显变化,且受裂纹角度影响显著。In order to study the effect of CMAS infiltration on temperature field,stress field and energy release rate near columnar intergranular microcracks,a numerical model of EB-PVD thermal barrier coating with microcracks was established. The effects of material constant,crack angle and crack length on microcrack tip field were analyzed. The effects of CMAS on microcrack characteristics were discussed in detail under cycle thermal loading,and the three different stages of effects of CMAS infiltration on stress field distribution were obtained. The results show that the stress at the crack tip increases significantly with the increase of CMAS infiltration depth and thermal mismatch between coatings. With the increase of CMAS infiltration time,the thermal insulation performance of the coating decreases,and the stress at the crack tip increases significantly,which is easy to cause delamination and peeling failure of the coating. With the increase of CMAS infiltration depth,the temperature field,stress field and energy release rate of crack tip change obviously,and are affected by the crack angle significantly.

关 键 词：热障涂层 钙镁铝硅酸盐 循环热载荷 裂纹 应力 能量释放率 航空发动机 

分 类 号：V263.3[航空宇航科学与技术—航空宇航制造工程]