新型Ni－Fe－W－S合金刷镀层耐磨性的研究

A Study on Wear Resistance of New Type Ni-Fe-W-S Alloy Brush Plating Layer

镀铬是用于提高材料常温耐磨性的有效方法。但是，铬镀层在摩擦温升的作用下，其硬度和耐磨性却都下降，而且镀铬还会污染环境和对人体造成损害．为了克服铬镀层和镀铬工艺的这些缺点，研究了一种新型的Ｎｉ－Ｆｅ－Ｗ－Ｓ合金刷镀层，摩擦磨损试验结果表明，在于摩擦时于高速（７１ｍ／ｍｉｎ）和重载（８０Ｎ）条件下，这种合金刷镀层的耐磨性能明显地比铬镀层的好，磨痕形貌的扫描电子显微镜观察发现，前者发生的是应变疲劳磨损，而后者已经发生了严重的粘着磨损．同时，通过对高速重载干摩擦条件下平均温度和闪温的计算，并且利用Ｘ射线衍射仪和透射电子显微镜等对磨损前后镀层的相结构及显微组织的分析，探讨了Ｎｉ－Ｆｅ－Ｗ－Ｓ合金刷镀层在如此苛刻条件下具有较高硬度和良好耐磨性能的机理，指出这是在摩擦热的作用下合金刷镀层中部分非晶向晶态转化前发生微观结构畸变并形成了更多硬质相的结果．

The chromium plating is an effective method for the improvement of wear-resistance ofmaterials at normal temperatute;However,the hardness and wear-resistance of chromium platinglayer will be decreased due to the temperature rise on contact surface by friction,and the chromiumplating process can induce pollution of environment and is harmful.In order to overcome thesedrawbacks,a new tyl1e Ni-Fe-W-S alloy brush plating layer was developed.The results of frictionand wear tests show that its wear resistance under the conditions of high load(80N), high speed(71m/min)and dry friction is obviously better than that of chromium plating layer.The scanningelectron microscope(SEM)observation of wear track indicates that the wear mechanism of theformer is strain fatigue,and that of the latter is severe adhesion,Finally,the mechanism of its highhardness and good wear-resistance under such harsh conditions is discussed through the calculation offriction temperature(including mean and flash temperatures)and analyses of X-ray diffraction andtransmission electron microscope(TEM).It was indicated that the microstructural distortion ishappened and more hard phase is formed before converting the partial non-crystalline into crystalstate in the alloy brush plating layer under the effect of heat of friction.