热生长下热障涂层残余应力及失效分析  

Residual Stress and Failure Analysis of Thermal Barrier Coatings with Thermal Growth

作　　者：孙戬[1] 徐颖强[1] 李万钟[1] 陈亚亚[1] 吕凯[1] 

机构地区：[1]西北工业大学机电学院,西安710072

出　　处：《中国表面工程》2016年第1期25-31,共7页China Surface Engineering

基　　金：国家自然科学基金(11072196;5875214;10672134);陕西省自然科学基金(2015JM1009)

摘　　要：针对典型热障涂层结构以界面开裂和涂层剥落为主要失效模式,考虑界面凹凸微观形貌特征,借助材料转换的方法实现氧化生长,利用粘弹塑性有限元法,研究了氧化层热生长和蠕变等因素对热障涂层残余应力的影响,并从应力应变循环演化的角度对热障涂层系统中微裂纹的萌生位置进行了预测。结果表明,随着氧化层厚度的增大,垂直于界面方向的残余应力迅速增大;材料蠕变对热障涂层系统应力释放作用显著;从残余应力和应变演化的角度进行评价,结构中的微裂纹会率先出现在粘接层凸峰以及陶瓷层/氧化层/黏结层界面的中间位置,仿真分析结果与试验结果一致。In view of the interfacial cracking and spallation as primary failure modes in typical thermal barrier coatings（TBCs）,considering the convex/concave microscopic characteristics and the thermal growth with material property change method,the influence of thermal growth and material creep on residual stress of TBCs was studied using an elastic-plastic finite element method.Then,the micro-crack initiation location was forecasted with the estimation of the stress-strain evolution behavior.It is concluded that the residual stress in vertical interface direction rapidly increases with thickening thermal growth oxides（TGO）.The material creep significantly affects stress relief on TBCs.The micro-crack will appear in the bond-coat（BC）convex and top-coat（TC）/TGO/BC interface intermediate positions from the point of view of residual stress and strain evolution behavior,which is consistent with the experimental results.

关 键 词：热障涂层 热生长 蠕变 应力 应变 

分 类 号：TG174.442[金属学及工艺—金属表面处理] TG113.25[金属学及工艺—金属学]