铬离子注入改善纯铁摩擦学特性的研究

The Tribological Properties of Pure Iron Surface Modified by Cr +-lmplantation

为了探讨离子注入改善金属和合金材料减摩抗磨性能的作用机理，对３种剂量的Ｃｒ离子注入纯铁改性层的元素深度分布和显微硬度进行了考察，并对离子注入和未经离子注入试样在无润滑下的摩擦学性能作了对比试验研究．结果表明：在给定的试验条件下，Ｃｒ离子剂量为１×１０１７ｉｏｎｓ／ｃｍ２注入的表面改性效果最好，可使纯铁的显微硬度由未注入时的２．４ＧＰａ提高到３．０ＧＰａ；在相对湿度为８８％的大气环境中，注入试样的摩擦系数比未经注入试样的约低５０％，耐磨性比后者的高２～３倍．Ｘ射线光电子能谱等分析发现，Ｃｒ离子注入能促进纯铁表面形成氧化物膜．在相对湿度为５０％时，氧化物膜主要由Ｆｅ２Ｏ３组成；在相对湿度为８８％时，这种膜主要由Ｆｅ２Ｏ４组成．因此。

In order to inquire into the mechanism of the antifriction and antiwear properties of metal or alloy improved by ion-implantation,the microhardness and Cr element depth profile of Cr +-implanted pure iron with three different doses were examined,and the friction and wear properties of the implanted and unimplanted specimens were investigated under unlubrication conditions.The results showed that the microhardness of pure iron modified by Cr +-implantation of 1×10 17 ions/cm 2 doses is the best,the microhardness increases from 2.4 GPa to 3.0 GPa in given test conditions,the friction coefficient of the implanted specimen is equal to 50% of the unimplanted specimen,wear-resistance increases by 200%～300% as the relative humidity is 88% under atmosphere condition.It is found that through analyses of X-ray photo electron spectroscopy(XPS)on the worn surfaces,that Cr +-implantation can promote pure iron surface to produce oxide film,the oxide film in the worn surface is mainly comprised of Fe 2O 3 in relative humidity being 50%,but the oxide film in the worn surface is mainly comprised of Fe 3O 4 as the relative humidity is 88%,thus the antifriction and antiwear properties of the implanted specimens is fine in the high relative humidity.