干摩擦条件下天然橡胶／钢的磨损机理研究

采用FALEX试验机考察了20^#钢／天然橡胶在干摩擦条件下的磨损机理。用扫描电子显微镜分析了20^#钢和橡胶磨损表面形貌。用X射线光电子能谱仪分析了金属和橡胶磨损表面元素的含量及化学状态，用镜面全反射傅立叶红外光谱仪分析了橡胶磨损表面官能团的变化。结果表明，20^#钢／天然橡胶摩擦副发生了粘着磨损，其磨损机制为：金属及金属氧化物与天然橡胶分子自由基在摩擦表面发生反应；在亚表层以金属与大分子自由基的反应为主，主要产物为含有Fe-C的金属－聚合物；金属本身发生氧化，主要产物为Fe2O3,FeO和Fe3O4，而在亚表层的主要产物以FeO为主，表面膜可能通过化学键、静电作用力和分子间的范德华力与金属基体相结合。

Wear Mechanisms of AISI1020 Steel against Natural Rubber under Dry Sliding

The wear mechanisms of AISI1020 steel by natural rubber under dry sliding were investigated. Thus the original and worn surface morphologies of and the elemental compositions and chemical states of the steel and rubber were observed and analyzed by means of scanning electron microscopy equipped with energy dispersive X ray analysis attachment and X ray photoelectron spectroscopy. The functional groups on the original and worn surfaces of the natural rubber were analyzed by means of Fourier transform infrared spectroscopy. It has been found that the wear of AISI1020 steel by natural rubber is mainly characterized physically by interfacial adhesion, while chemically by mechanochemical reactions between the surfaces of the steel and natural rubber, accompanied by the surface oxidation of the steel. The iron atoms and oxides on the steel surface react with the macroradicals of the natural rubber, therefore the products such as Fe polymer compound and ferrous oxide polymer complex are generated. Moreover, at the subsurface of the steel, the activated iron atoms react with the macroradicals and produces Fe polymer complex. The main oxides on the steel surface are Fe 2O 3, FeO and Fe 3O 4, while that at the steel subsurface is FeO. This is because the transfer film on the steel surface helps to restrain the oxidation of the steel. Moreover, the transfer film of different characteristics as compared with the steel substrate is also effective to reduce the friction and wear of the steel, by keeping off the direct contact between the rubbing surface of the steel and the natural rubber and restraining the abrasive action of the wear debris.