基体曲率对热障涂层残余应力的影响

The Effect of Substrate Curvature on Residual Stress of Thermal Barrier Coatings

导出了轴对称温度应力状态下的位移公式,采用空心和实心四相同心圆模型分析了基体曲率对热障涂层残余应力的影响。结果表明:热障涂层结构中各层内既有环向应力,又有径向应力,应力大小与温降成线性关系;当陶瓷层在外层时,在氧化层/陶瓷层和粘结层/氧化层界面上产生垂直界面的拉应力,且实心模型的拉应力远大于空心模型的拉应力;当陶瓷层在里层时,空心模型中相应界面上的应力为压应力。

Deduced displacement formula of axis symmetry temperature stress state. Hollow and solid concentric-circle models were used to consider the effect of TBC component surface curvature on residual stress. The main results are as follows ： in addition to the circular stress, radial stress would be generated at every layer of TBCs with the presence of curvature,, and the stresses exhibit a linear relationship with temperature drop. Tensile radial stress would appear at the ceramic/TGO and TGO/bond coat interface when ceramic coating is on the outside surface,and the stress of solid model is much larger than the hollow model. Compressive radial stress would appear when ceramic coating is on the inner surface of the hollow model.