加注稀土元素铒改善轴承表面性能的研究

Improvement in Surface Behavior of Bearing by Adding Rare-Earth Element lmplantation

在Ｍｏ￣＋＋Ｎ￣＋注入模式的基础上，应用电子能谱、卢瑟福背散射谱、扫描电子显微镜和ＭＨＫ－５００型摩擦磨损试验机等研究了加注稀土元素铒正离子Ｅｒ￣＋对轴承表面摩擦学性能和耐蚀性能的影响．结果表明，在合理配置Ｍｏ￣＋、Ｎ￣＋、Ｅｒ￣＋之能量和剂量的情况下，加注Ｅｒ￣＋既能更好地改善轴承的表面性能，又能使重离子的强韧化效果提高２－４倍以上，表明Ｍｏ￣＋＋Ｎ￣＋＋Ｅｒ￣＋注入模式是一种具有良好应用前景的轴承表面强韧化方法。

The effective method to strengthen the surface of bearing by the mode of Mo++N+ implantation has been suggested.The influence of additional rare-earth Er+ implantation on thetribological and corrosion-resisti ng behavior of the bearing surface has been studied. There are twosorts of samples A and B,samole A was made of 20Cr2Ni4A carburizing steel and B20CrNi2MoA. The samples were prepared according to the cold and heat processing technology ofthe huge bearing,Ra≤0. 063μm,HRC=62 for surface,HRC=45 and HRC=43 for corerespectively. The mode of Mo+(500keV, 200keV, 2×1.00×1016m-2)+N+(150keV,3.00×1017cm-2)implantation was used for A2 and B2 samples;the mode of Mo+(500keV, 200keV,2×2.50×1015cm-2)+N+(100keV,3×1017cm-2)+Er+(350keV,2×1015cm-2)for A4 and B3samples. The doses of Mo+ for A 4 and B3 were decreased by three-four and nine-tenths times ascompared with A2 and B2 respectively, and the dose of the total heavy ions was decreased by two-thirds and four-fifths times respectively. The steady-state temperature of the samples governed bythe low-temperature target was below 120℃, The HRC of the implanted samples was still 62.The distribution and phases construction uf element Mo,N, Er.Fe,C,O in the implantedfilm was analyzed by AES-PRO techniques.The results shown that the disrposition of energies anddoses for three ions are rational basically,The oxides of Er and Fe-Er metallic compounds separatedout in the implanted film play an important effect upon the tribological and corrosion-resistingbehaviors.The tribological and corrosion-resisting performance tests shown that the microhardnessHV0.004, HV0.050 and contact fatigue life L10,L50,Vs for sample A4 are increased by 3.0%,0.7%,18.1%,18.2% and 17.3% than those of sample A2 respectively. The strengthening-tougheningefficiency of heavy ions is increased by a factor of at least 2. Similarly for sample B3 by 13.7%,0.4%,0.8%,14.6% and 17.2% than those of sample B2 respectively,the efficiency by afactor of at least 4; the corrosion and wear resistances, roughnerss and lubrication of surface areimproved,too. The average related wear resistance(ARWR) for B3 is increased by 13% than thatof sample B2; the critical passivity and passivity current density, roughness of surface and abrasionafter testing μ Ra, friction coefficient μ for B3 are decreased by 22.0%, 36.0%,8.0%, 10.0%and 5.0% than that of sample B2 respectively, It can be concluded that the effect of thestrengthening-toughening by Er+ implantation is significant. The mode of Mo++N++Er+ implantation is a comparatively ideal method to strength-toughen the bearing surface.