影响热障涂层失效因素的研究现状及展望

Review on the Failure Factors of Thermal Barrier Coatings

热障涂层(TBCs)具有良好的隔热性能,是燃气轮机高温部件的关键材料,在高温服役过程中,涂层脱落会导致部件工作失效,因此为获得长寿命热障涂层,涂层的脱落失效机理是急需深入研究的问题。综述了热应力、α-Al_2O_3生长、外应力、热生长氧化层(TGO)起伏及孔隙率等缺陷对涂层应力发展的影响,探讨了微裂纹的产生、扩展及脱落的失效过程,最后展望了研究热障涂层失效及提高涂层寿命的努力方向和前景。

Thermal barrier coatings have favorable heat insulation performance, which makes them as the high- temperature materials of gas turbine. The coating spallation would lead to components failure during the gas turbine operating at high temperature. Therefore, the failure mechanism of coating had become an urgent problem to get long- lifetime thermal barrier coatings. The effects of thermal stress, αAl2O3 growth, exterior stress, fluctuation of thermally grown oxide （TGO）, porosity and other defects on the stress development of the coatings are reviewed. In addition, the production, propagation and spallation of micro-cracks are analyzed. Finally, the future study emphases of thermal barrier coatings failure mechanism and how to prolong the life time are anticipated.