Effect of current polarity on electrical sliding wear behavior of Cu-WS_2-graphite-WS_2 nanotube composites in air and vacuum conditions  

作　　者：QIAN Gang FENG Yi CHEN FanYan LIU WenHong ZHANG XueBin LIU YanFang 

机构地区：[1]School of Materials Science and Engineering,Hefei University of Technology

出　　处：《Science China(Technological Sciences)》2013年第11期2839-2846,共8页中国科学（技术科学英文版）

基　　金：supported by the Major Research Program of the National Natural Science Foundation of China(Grant No.91026018);the National Natural Science Foundation of China(Grant No.60979017);the Doctoral Fund of Ministry of Education of China(Grant No.20110111110015)

摘　　要：In this paper Cu-WS2-graphite-WS2nanotube composites were fabricated by powder metallurgy hot pressing method.The effect of current polarity on the wear rates and contact voltage drops of the composites were investigated using a brush-on-slip ring tribometer rubbing against Cu-5 wt.%Ag alloy ring in air and vacuum,respectively.The worn surfaces of the composites were analyzed by scanning electron microscopy(SEM)and X-ray photoelectron spectroscopy(XPS).Surface profile curves of the worn tracks were measured using the surface profiler.The results demonstrated that the current polarity has a significant effect on the wear rates and contact voltage drops of the composites in both air and vacuum conditions.Positive brush possesses a higher wear rate compared with the negative brush in the air atmosphere since the electrical field direction activates oxidation at the positive brush surface while inhibits oxidation at the negative brush surface.Except for the regular wear losses,the combined effect of molten metal bridge erosion and arc erosion cause the positive brush to lose extra material and the negative brush to gain extra material,so the positive brush shows a higher wear rate in the vacuum condition.The contact voltage drop of the positive brush is lower than that of the negative brush in the air atmosphere,but contrarily,the positive brush shows a higher contact voltage drop in the vacuum condition.

关 键 词：Cu-WS2-graphite-WS2 nanotube composites current polarity air and vacuum conditions wear rate contact voltage drop 

分 类 号：TB33[一般工业技术—材料科学与工程]