含抗氧化夹层热障涂层界面应力特性的研究

INVESTIGATION OF INTERFACIAL STRESS IN THERMAL BARRIER COATINGS WITH OXIDATION-RESISTANCE INTERLAYER

通过喷涂等工艺技术,在热障涂层粘结层和陶瓷层之间预制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夹层又会导致热障涂层界面应力场重新分布。文中针对热障涂层界面三维形貌特征,利用弹性理论中的空心球模型,考虑陶瓷层(ZrO2层)、夹层(Al2O3层)、氧化层(thermally grown oxide,TGO)及粘结层(bondcoat,BC),建立三维四层球模型的理论分析,并推演出相应的应力解析式。文中通过凹凸两种界面形貌下抗氧化夹层的算例分析,表明以上分析方法能有效模拟夹层对热障涂层界面应力分布规律的影响。

Hasma-sprayed Al2O3 interlayer was prefabricated between the bondcoat and topcoat in thermal barrier coatings. It can prevent oxygen penetration through the interconnected porosity in the topcoat, so that the TGO（ thermally grown oxide） growth and the failure can be suppressed. But, prefabricated Al2O3 interlayer will result in inteffacial stress redistributing. Basing on three-dimensional shape of thermal barrier coatings, using elastic sphere model, eonsidering topcoat, interlayer, TGO and bondcoat, have developed a four-concentric-sphere model of three-dimensional, and produced the relevant analytical model. The analysis of anti-oxidation layer for the concave and convex asperity, indicate that the method can simulate the effect of interlayer on the interracial microstructure＇ s stress distributing of thermal barrier coatings.