基体条件对Sm2Zr2O7/YSZ双陶瓷层热障涂层界面残余热应力的影响

采用有限元分析软件ANSYS对等离子喷涂Sm2Zr2O7/YSZ双陶瓷层热障涂层界面残余热应力分布进行了数值仿真。结果表明:基体厚度不同时,涂层界面Sm2Zr2O7/YSZ及界面YSZ/NiCoCrAlY对应应力及应力梯度基本不变,表明应力及应力梯度与基体厚度无关;但基体材质热膨胀系数对涂层系统界面的径向、轴向及剪切应力梯度有决定性的影响,且各应力梯度随金属基体的热膨胀系数差异增加而增大,表明基体材质是影响涂层界面径向残余热应力及应力梯度的根本原因。采用多层陶瓷结构并合理选择各层材质的热膨胀系数将更加有利于降低涂层应力梯度,进而改善涂层性能,延长涂层寿命。

THE EFFECT OF RESIDUAL THERMAL STRESSES AT THE INTERFACE OF Sm2Zr2O7/YSZ DOUBLE CERAMIC THERMAL BARRIER COATINGS BASED ON MATRIX CONDITIONS

The distribution of residual thermal stresses at the interface of Sm2Zr2O7/YSZ double ceramic thermal barrier coatings were simulated by using ANSYS software.Results show that the residual thermal stresses and the stress gradient at the interfaces of Sm2Zr2O7/YSZ and YSZ/NiCoCrAlY don’t change with the thickness of the matrix,but the stress gradients increase with increasing of metal substrate thermal expansion coefficients.It is also indicates that the residual thermal stresses and the stress gradient depend on Matrix materials,and it will be more conducive to reducing coating stress gradient,improving coating performance and extending the life of coating by using multilayer ceramic structure and reasonable choices the material thermal expansion coefficient of each layer.