(1. 中国科学院 力学研究所，北京100190；
2. 中国科学院研究生院，北京100049)
摘 要: 重载作用下，类金刚石(DLC)薄膜直接应用于铝合金等软金属基体上易发生脆性破裂和剥离而导致过早失效。针对这一问题，以PEO陶瓷层作为承载层，采用有限元数值计算方法，对复合涂层在均布接触载荷作用下的应力场进行研究。结果表明：陶瓷层可明显降低DLC膜的表面拉应力和界面剪应力，起到了良好的载荷支撑作用；陶瓷层厚度对涂层表面拉应力、界面及基体内剪应力的分布有显著影响，其中陶瓷层厚度与接触半宽比为0.15~0.30时，涂层可以获得较为合理的表面和界面应力场，从而改善DLC膜在铝合金基体上的摩擦磨损性能。
关键字: 铝合金；PEO陶瓷层；DLC膜；承载层；有限元；应力场
DLC films on aluminum substrate
（1. Institute of Mechanics, Chinese Academy of Science, Beijing 100190, China;
2. Graduate University, Chinese Academy of Science, Beijing 100049, China）
Abstract:Under heavy load, DLC film that directly applies to such soft metal substrates as aluminum alloy are prone to premature failure caused by brittle fracture and stripping. To solve this problem, PEO ceramic layer was made as a bearer layer, and the stress field of the composite coating subjected to uniform contact load was investigated by finite element method(FEM). The results show that the surface tensile stress and interface shear stress of the diamond-like carbon(DLC) film are obviously reduced by the ceramic layer, which plays a good supporting role in the load. Meanwhile, the surface tensile stress and the shear stress are significantly affected by the thickness of ceramic layer. While the ratio of ceramic layer thickness to contact radius is 0.15−0.30, more reasonable stress fields at surface and interfaces can be got, thereby the friction and wear properties of the DLC film on aluminum substrate are improved.
Key words: aluminum alloy; PEO ceramic layer; DLC films; bearer layer; finite element; stress field
