热障涂层抗氧化夹层界面残余应力分析

Analysis of Interfacial Residual Stress in Thermal Barrier Coatings Containing Oxidation-resistance Interlayer

通过喷涂等工艺预制的Al2O3夹层能有效抑制热障涂层高温不规则氧化生长及其所导致的失效。但是,预制的Al2O3夹层又会导致其界面应力重新分布。针对热障涂层界面三维形貌特征,考虑陶瓷层(ZrO2层)、夹层(Al2O3层)、氧化层及粘结层,建立了三维四层球模型,并推导出相应的应力解析式。凹凸两种界面形貌下抗氧化夹层的算例分析表明,抗氧化夹层厚度对热障涂层界面残余应力分布规律有很大的影响。

Plasma -- sprayed Al2O3 interlayer penetration through the interconnected porosity in which was prefabricated can prevent oxygen the topcoat, so that the thermally grown oxidation （TGO） growth and the failure can be suppressed, however, the prefabricated Al2O3 interlayer will result in interfaeial stress redistribution. A four- concentric- sphere geometrical model, made up of topcoat, interlayer,TGO,and hondcoat,was developed based on three--dimensional shape of thermal barrier coatings. And the behavior of relevant interracial residual stress depending on Al2O3 interlayer thickness for models of concave and convex morphology respectively was studied. The results show that the thickness of Al2O3 interlayer has a great effect on the interfacial residual stress distribution of thermal barrier coatings.