等离子涂层涡轮导向叶片热疲劳寿命预测研究

针对等离子涂层涡轮导向叶片材料的变形特点,引入了粘塑性本构模型.进行了涂层高温氧化实验、带涂层构件热疲劳实验及有限元模拟研究.基于研究结果,建立了可以体现氧化损伤与热疲劳损伤耦合效应的寿命预测模型.计算分析了带涂层涡轮导向叶片的稳态温度场、涂层隔热效果和基于宏观尺度的应力应变场,研究了宏、细观有限元计算结果间的转换关系,提出了等效系数的方法,对涡轮导向叶片表面涂层的热疲劳寿命进行了预测.寿命预测结果合理,方法可行. 

Study on thermal fatigue life prediction for plasma sprayed thermal barrier coatings on the surface of turbine vane

According to the deformation characteristics of plasma sprayed ceramic thermal barrier coatings(TBC) and directional solidified superalloy substrate,viscoplastic constitutive models were introduced.Static oxidation test and thermal fatigue test of thermal barrier coating structures were conducted along with related FEM analysis.A life prediction model for TBC was established for presenting the coupling effect of oxidation damage and thermal fatigue damage.The steady temperature field,thermal barrier effect,and the macro-scale stress/strain fields of 3-dimensional turbine vane with TBC were calculated and analyzed.The relationship between macro and micro-scale under scanning electronic microscopy of FEM(Finite Element Method) results was investigated.A method of equivalent coefficient was proposed while the thermal fatigue life for TBC on the surface of turbine vane was predicted,showing that the life prediction results are reasonable and the method is feasible.