热障涂层皱曲的力学模型研究进展

Progress in Research on the Mechanical Models of Rumpling in TBCs

在EB-PVD/(NiPt)Al涂层中存在皱曲(Rumpling)现象,导致涂层的早期失效。综述了皱曲(Rump-ling)力学模型的研究进展,主要包括3个方面的问题:皱曲的力学模型、数值计算方法研究现状;皱曲的机理及力学模型研究中存在的问题和不足;进一步研究皱曲机理并改进模型的途径。提出了在粘结层晶体尺度内棘轮效应与热扩散间存在耦合作用的设想,并认为这种耦合作用是形成皱曲的根本原因。

The multi-layer thermal barrier systems based on Pt-modified nickel aluminide bond coats and electron beam deposited thermal barrier coatings （TBCs） have a tendency of rumpling. In the presente paper, the progress in research on mechanical models of rumpling and related finite element method are reviewed and discussed. The analysis suggests that ratcheting as the most popular model is not perfect and the underlying mechanism of rumpling still remains to be established. It is proposed that there may be a coupling between the ratcheting and thermal diffusion in the scale of grains,and the coupling is the fundamental cause of rumpling.