双涂层界面接触应力分析

Analysis of the Contact Stress at Interface of Double Coatings

目的研究在接触应力作用下,双涂层的总厚度及厚度比对其界面应力的影响规律。方法采用有限元方法研究两个界面,即涂层与基底界面和涂层间界面的Mises应力突变量和界面最大剪应力。结果总厚度一定时,涂层厚度比变化对涂层/基底界面应力的影响较小,而对涂层间界面应力的影响明显。对于薄涂层,涂层间界面Mises应力突变量和最大剪应力随着中间层厚度比例的增大而减小;对于厚涂层,涂层间界面Mises应力突变量和最大剪应力随着中间层厚度比例的增大而减小。涂层厚度比一定时,随着涂层总厚度增加,涂层间界面Mises应力突变量和最大剪应力先增大,后减小。结论双涂层的总厚度及厚度比对其界面应力有显著影响。

Objective To investigate the influences of the coating thickness and interlayer-to-top layer coating thickness ratio tint ： ttop on the interface stress in the TiN-interlayer coating/substrate under contact stress. Methods Using Finite element method, the Mises stress gradient and the maximum shear stress at one interface between the coating and the base and the other between the top layer coating and the interlayer coating were studied. Results The coating thickness t and the interlayer-to-top layer coating thickness ratio t^n, ： ttop had little influence on the interface stress between the coating and the base,however, they showed obvious influence on the interface stress between the top layer and the interlayer coating. For the thin coating, the Mises stress gradient and the maximum shear stress at the interface between the top layer and the interlayer were decreased when the interlayer-to-top layer coating thickness ratio t^nt ： ttop increased, while for the thick coating, the Mises stress gradient and the maximum shear stress at the interface between the top layer and the interlayer were increased when the interlayer-to-top layer coating thickness ratio tint ： ttop de- creased. For the same interlayer-to-top layer coating thickness ratio tint ： ttop, the Mises stress gradient and the maximum shear stress were first increased and then decreased when the coating thickness increased. Conclusion The coating thickness and the thickness ratio showed distinct influences on the interface stress of a double coating system.