CoCrMo合金表面掺金属类金刚石薄膜的摩擦学性能

采用非平衡磁控溅射结合阳极型气体离子源技术在CoCrMo合金表面制备掺钨类金刚石薄膜(WDLC)和掺钛类金刚石薄膜(Ti-DLC)。利用努氏显微硬度计、结合力划痕仪、摩擦磨损试验机、表面形貌仪和洛氏硬度计表征膜层的力学性能,并用扫描电镜分析磨损形貌,探讨薄膜磨损机理。结果表明:所制备的2种薄膜均具有典型的DLC薄膜特征,W-DLC薄膜的硬度、结合力和摩擦磨损性能均优于Ti-DLC薄膜,更适合于CoCrMo合金的表面强化处理;CoCrMo合金的磨损机制主要为粘着磨损和磨粒磨损,而Ti-DLC/CoCrMo和W-DLC/CoCrMo的磨损机制以滑动磨损为主伴随极少量的磨粒磨损;经DLC薄膜处理,摩擦因数从CoCrMo合金的0.578降低到0.2以下,磨损率也降低了2个数量级,大幅度地提高了CoCrMo合金的摩擦磨损性能。

Tribological Performance of Metal Doped Diamond-like Carbon Films Deposited on CoCrMo Alloy

WDLC films and TiDLC films were deposited on CoCrMo alloy by unbalanced magnetron sputtering (UMS) combined with ion source technique. Mechanical properties were evaluated by Knoop microhardness tester, scratching tester, friction and wear tester, and MicroXAM3D morphology tester, respectively. The wear morphologies of DLC films and CoCrMo substrate were analyzed by SEM. Besides, the wear mechanisms were investigated carefully. The results show that the two types of films have typical characteristics of DLC films. The microhardness, adhesion and tribological performance of the WDLC film are better than that of the TiDLC film and more suitable for surface strengthening on CoCrMo alloy. The wear mechanisms of the CoCrMo substrate are adhesive and abrasive wear. However, the sliding wear plays a main role in TiDLC and WDLC films and combined a little abrasive wear. The friction coefficient of CoCrMo alloy is reduced from 0.578 to below 0.2, and the wear rate decreases by two orders after being coated with DLC films which significantly improves the tribological performance of CoCrMo alloy.