类金刚石膜与表面织构双重改性下CoCrMo合金摩擦性能研究

Tribological Properties of CoCrMo Alloy Surface-Modified by Laser Texturing and with Diamond-Like-Carbon Coating

研究采用类金刚石碳(DLC)薄膜和表面织构双重改性技术对CoCrMo合金进行了表面处理,借助摩擦试验研究配副系统的摩擦性能,并分析了摩擦和磨损机理。结果表明,改性前的CoCrMo/超高分子量聚乙烯(UHMWPE)配副在生理盐水溶液润滑下的摩擦系数低至0.05。当接触压力为3.5 MPa时,DLC薄膜改性后的配副在牛血清白蛋白(BSA)溶液中平均摩擦系数为0.25,在生理盐水中的平均摩擦系数为0.42;DLC薄膜和表面织构双重改性处理的配副在BSA溶液和生理盐水润滑下的摩擦系数分别为0.23和0.31,表明改性处理不能发挥减摩效果。未改性的CoCrMo试样在生理盐水润滑下磨损表面存在大量UHMWPE磨屑,并且UHMWPE磨屑发挥自润滑作用。改性处理提高了CoCrMo试样盘的耐磨性能,却抑制了UHMWPE磨屑在CoCrMo试样盘表面的粘附。双重改性表面在存储磨损磨屑和提高表面耐磨性能方面具有协同效应。

The laser-textured surfaces of CoCrMo alloy,an advanced artificial human joint material,were further modified with diamond-like-carbon(DLC) coatings,synthesized by close field unbalanced magnetron sputtering ion plating.The friction-coefficient and wear-resistance of the mating-pair,comprising the control and DLC-coated CoCrMo samples and ultra-high molecular weight polyethylene(UHMWPE),were investigated with scanning electron microscopy and energy dispersive spectroscopy in BSA solution and normal saline,respectively.The preliminary results show that the modification by laser-texturing and DLC-coating had a major impact.For example,the DLC-coated CoCrMo/UHMWPE pair had much higher friction-coefficient,significantly lower wear-rate(or stronger wear-resistance),considerably fewer sticky UHMWPE-debris and sizable shallower wear-tracks than the bare CoCrMo/UHMWPE pair.In addition,the UHMWPE wear-debris was found to be good self-lubricant for the DLC-coated CoCrMo/UHMWPE pair.