Tribological properties of kaolin filled UHMWPE composites in unlubricated sliding

The two kinds of kaolin filled ultra-high molecular weight polyethylene (UHMWPE) based composites (UHMWPE/kaolin) were prepared by means of polymerization filling and melt mixing, respectively. The unlubricated sliding wear behavior of the composites was tested on an MM200 rig. The effects of sliding speed and load on the sliding wear of UHMWPE were determined. Scanning electron microscopy (SEM) was employed to examine the worn surfaces and the wear mechanisms of the composites discussed. It has been found that appropriate kaolin filling can greatly improve the tribological behavior of UHMWPE. It has also been found that the UHMWPE/kaolin composites prepared by polymerization have much better tribological properties than the ones prepared by mixing with the same components and are promising self-lubricated material candidates for engineering application.