目的 通过表面等离子W-Mo合金化提高粉末冶金齿轮硬度与耐磨性能。方法 采用双层辉光等离子表面冶金技术，在粉末冶金齿轮表层制备W-Mo合金层。通过扫描电镜和能谱仪分析合金层的表面形貌和化学成分，用显微维氏硬度仪测量基体与合金层的显微硬度，通过不同载荷下往复式摩擦磨损实验研究等离子W-Mo合金化对粉末冶金齿轮耐磨性能的影响。结果 通过双辉等离子冶金技术在粉末冶金齿轮表面成功制备了W-Mo合金层，合金层与基体为冶金结合。经双辉等离子表面W-Mo合金化后的基体的平均显微硬度由之前的145.8HV0.1提升至344.4HV0.1，提升了约1.4倍。不同载荷下的摩擦磨损实验结果表明，经W-Mo合金化后，试样摩擦系数由0.6~0.7降至0.45~0.5左右，下降了约30%。随着载荷的增加，基体与合金层的磨损体积增加，比磨损率由基体的18.70×10^?5~36.16×10^?5 mm³/(N.m)降至合金层的2.99×10^?5~ 8.79×10^?5 mm³/(N.m)，约下降74%~84%。基体存在磨料磨损和粘着磨损现象，而W-Mo合金层则表现出轻微的磨料磨损。结论 W-Mo合金层显著提升了粉末冶金齿轮的硬度和耐磨性。表面等离子W-Mo合金化为粉末冶金齿轮的表面强化工艺提供了新的技术思路。

The work aims to improve the hardness and wear resistance of powder metallurgy gear through surface plasma W-Mo alloying. The W-Mo alloy coating was prepared on the surface of powder metallurgy gear by double glow plasma surface metallurgy technology. The surface morphology and chemical composition of the W-Mo alloy coating was characterized by scanning electron microscope (SEM) and energy dispersive X-ray spectroscope (EDS). The microhardness of the substrate and W-Mo alloy coating was measured by Vickers microhardness tester. The effect of plasma W-Mo alloying on the abrasion resistance of powder metallurgical gears was studied by reciprocating friction and wear experiments under different loads. The W-Mo alloy coating was successfully prepared on the surface of powder metallurgy gear by double glow plasma metallurgy technology. The alloy coating was metallurgically bonded with the substrate. The average microhardness of substrate increased from 145.8HV0.1 to 344.4HV0.1 after double glow plasma surface W-Mo alloying, an increase of about 2.4 times. The friction and wear tests under different loads indicated that the friction coefficient declined from 0.6~0.7 to about 0.45~0.5 after W-Mo alloying, a decrease of about 30%. With the increasing of the load, the wear volume of the substrate and the W-Mo alloy coating increased. The specific wear rate decreased from 18.70×10?5~36.16×10?5 mm3/(N.m) of the powder metallurgy gear to 2.99× 10?5~8.79×10?5 mm3/(N.m) of the W-Mo alloy coating, which was a decrease of about 74%~84%. The wear mechanism of the substrate consisted of adhesive wear and abrasive wear, while wear mechanism of the W-Mo alloy coating was slight abrasive wear. The W-Mo alloy coating improves the hardness and wear resistance of powder metallurgy gear significantly. The surface plasma W-Mo alloying technology provides a new technical method for the surface strengthening of powder metallurgy gear.