纳米Fe_2O_3颗粒填充UHMWPE复合材料摩擦表面的原子力显微分析

AFM analysis of micro-wear mechanisms in nano-Fe_2O_3 particle reinforced UHMWPE composite

用纳米Fe2O3颗粒填充超高分子量聚乙烯(UHMWPE)制备纳米复合材料。在MM200型摩擦磨损试验机上考察复合材料的摩擦磨损特性,用原子力显微镜观察分析复合材料摩擦表面的微观形貌,综合分析材料摩擦磨损的微观机理。结果表明,纳米Fe2O3颗粒填充UHMWPE可有效改善基体材料的摩擦学性能,其微观磨损机理由犁沟切削失效为主转化为微疲劳失效为主,在原子力显微镜下可以清楚地观察到在摩擦表面突起的纳米颗粒和摩擦过程中在基体中形成的疲劳痕线。纳米颗粒在基体中的分散是影响材料磨损性能的主要因素。当纳米颗粒出现团聚时,在颗粒周围会形成微裂纹,从而导致材料磨损加剧。

The ultra-high molecular-weight polyethylene （UHMWPE） filled with nano-Fe2O3 particle was prepared. The fraction and wear characteristics were investigated using the MM-200 tester. The micro-wear mechanisms of the composite were discussed through examining and analyzing the worn surface with Atomic force microscope. It has been found that uano-Fe2O3 particle is effectively to reduce the fraction and wear of UHMWPE. The major micro-mechanism of composite fraction is micro-fatigue wear but not the abrasive wear. The projecting nano- particles on the worn surface and micro-fatigue pattern forming on surface of UHMWPE composite during fraction can be clearly observed under AFM. The dispersity of nano-particles performs a key effect on the fraction and wear properties of composite. The micro-crack forming around the particles causes wear increase while nano-particles gathered in location.