涂层基体条件对梯度涂层残余应力影响研究

采用有限元法，对结构一定的Al/Ni-ZrO2梯度涂层在基体条件改变时涂层的残余应力进行了分析，结果表明，基体材料的热膨胀系数对涂层的残余应力有显著的影响，对于基体为圆柱形的涂层，其基体与涂层界面的残余应力梯度，最大轴向拉应力均随热膨胀系数的增大而线性增大，表面纯陶瓷层与次层界面残余应力梯度则随之减小，增大基体的直径和厚度，可缓和涂层残余应力，并在基体直径为36mm,厚度为20mm时各残余应力基本稳定。

Substrate Influence on Residual Stress of Gradient Coating

Finite element method was adopted in this paper to analyze substrate influence on residual stress of gradient coating when the substrate condition of gradient coating was changing, but the structure of gradient coating was unchanged The results show that the residual stress of gradient coating is affected remarkably by the thermal expansion coefficient of substrate material For the columnar substrate, both the difference of interface residual stress between substrate and coating and the maximal axial tensile stress increase linearly with the increasing of the thermal expansion coefficient, however, the difference of interface between ceramic layer and the second layer decrease To increase the diameter and the thickness of substrate can abate the residual stress of coating, and all kinds of residual stress are stable when the diameter of substrate is 36mm and the thickness is 20mm