热障涂层层状裂纹的位置对断裂性能的影响  

Effect of the Thermal Barrier Coatings Crack Positions on the Fracture Behavior

作　　者：徐颖强[1] 周忍[1] 

机构地区：[1]西北工业大学机电学院,西安710072

出　　处：《机械科学与技术》2008年第9期1217-1219,1224,共4页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家自然科学基金项目(10672134)资助

摘　　要：广泛应用于热能动力的热障涂层在高温工作环境下,由于温度梯度产生的热应力不匹配会导致热障涂层层裂或剥落失效。本文针对热障涂层层裂问题,考虑热应力不匹配因素,建立热障涂层层裂I/II复合型断裂准则,并针对分层裂纹在陶瓷层与粘结层界面上和附近的3种位置存在形式,进行了热障涂层结构单裂纹层裂的算例分析。结果表明界面处层裂纹对应变能释放率影响最大。Thermal barrier coatings （TBC） used widely for various components in the hot section of turbine engines experience temperature gradients which can cause thermal expansion mismatch between different layers. Residual stresses developed in TBCs during temperature circumstances induce coatings delamination and failure. In this paper, taking into account thermal stresses mismatch induced by thermal gradients, thermal barrier coating mixed Ⅰ/Ⅱ modes fracture criterion is modeled. Single crack delamination instances which include three different crack positions between ceramic coating and bond coating is analyzed. The results indicate that the effect of interface cracks on coatings fracture behavior is the most important.

关 键 词：热障涂层 层裂 断裂性能 

分 类 号：TB302.3[一般工业技术—材料科学与工程]