成型方法对PE-UHMW摩擦磨损性能的影响

Effects of Forming Methods on Friction and Wear Performances of PE-UHMW

采用对比试验的方法分别对模压成型法、机筒成型法制备的超高分子量聚乙烯(PE-UHMW)进行摩擦磨损性能研究。结果表明,采用机筒成型的PE-UHMW试样的磨合期较短,稳定区间摩擦系数为模压成型PE-UHMW试样摩擦系数的62.4%,机筒成型的PE-UHMW试样在载荷、转速变化的条件下摩擦系数表现更稳定;磨损量都呈现先快速增大后缓慢上升再快速增大的趋势,试验60 min后,模压成型PE-UHMW试样的磨损量为1.4 mg,机筒成型试样的磨损量为1.2 mg,机筒成型PE-UHMW试样的耐磨性能优于模压成型PE-UHMW试样;对试样摩擦磨损试验后的表面形貌的SEM分析表明,模压成型的PE-UHMW试样的摩擦机理主要为粘着磨损和疲劳磨损;机筒成型的PE-UHMW试样的摩擦机理以磨粒磨损和疲劳磨损为主,后期转化为粘着磨损。机筒成型的PE-UHMW试样摩擦磨损过程中的磨粒起到自润滑及减摩剂的作用,其热力学及力学性能优于模压成型的PE-UHMW试样。

Adopted contrast test method, the friction and wear performances of ultrahigh molecular weight polyethylene （PE- UHMW） forming from the compression molding and the barrel molding were studied. The results show that the running period of the PE-UHMW pipe forming from the barrel molding is relatively short, the stable friction coefficient is 62.4% of that forming from compression molding, and the friction coefficient is more stable under the condition of the load and the ~peed change. Dry friction wear loss is presented a trend from rapid increase at first to slowly rising then to rapid increase again. After 60 min, the wear loss of sample forming from compression molding is 1.4mg, and the wear loss of sample forming from the barrel molding is 1.2 mg, the friction and wear performance of sample forming from the barrel molding is better than one forming from the compression molding. SEM analysis of the morphology of the friction and worn surfaces after wear tests shows that the friction mechanism of PE-UHMW forming from the compression molding is mainly adhesive wear and fatigue wear, and the friction mechanism of PE-UHMW forming from barrel molding is mainly abrasive wear and fatigue wear, but late the mechanism change into adhesive wear. In PE- UHMW friction and wear process, the abrasive grains play a role of self-lubricating and friction reducing, and its thermodynamic and mechanical properties are better than that of PE-UHMW forming from the compression molding.