水润滑条件下高岭土填充UHMWPE基复合材料的摩擦学特性

TRIBOLOGICAL STUDIES OF KAOLIN FILLED UHMWPE COMPOSITES INSLIDING AGAINST STEEL LUBRICATED WITH WATER

分别用釜内聚合和机械混合两种方法制备高岭土填充UHMWPE基复合材料,对其在水润滑条件下的滑动摩擦磨损特性进行了试验研究,并通过对磨损表面形貌的观察分析,对材料的磨损机理进行了探讨。结果发现,水润滑对UHMWPE/Kaolin—45钢摩擦副的减磨(摩)作用显著;填充适量高岭土可以明显提高UHMWPE在水润滑条件下的摩擦磨损性能;釜内聚合方法制备的UHMWPE/Kaolin的磨损率相对较低,具有广阔的应用前景。

Kaolin filled ultra high molecular weight polyethylene (UHMWPE) based composites (coded as UHMWPE/Kao-lin) are prepared by polymerization filling and melt mixing, respectively. The friction and wear properties of the composites under sliding against AISI 1045 steel lubricated with water are evaluated with an MM-200 friction and wear tester. The morphologies of the worn composite surfaces and the transfer films on the counterface steel are observed by means of scanning electron microscopy (SEM) and stereo optical microscopy, and the wear mechanisms of the composites are discussed. The results show that, kaolin at a certain content is very effective to reduce the friction and wear of UHMWPE. UHMWPE/Kaolin composites prepared by polymerization filling are superior to the ones prepared by melt mixing with the same filler content in terms of reducing wear. Lubricated with water can obviously reduce the friction and wear of the composites and the effectiveness of the water lubrication is closely related to the characteristics of the composites. The differences in the effectiveness of water lubrication and the structure of UHMWPE/Kaolin account for the different friction and wear properties of the two kinds of composites.