电流及其极性对浸铜碳滑板摩擦磨损性能的影响

EFFECTS OF ELECTRICAL CURRENT AND ITS POLARITY ON THE PROPERTIES OF FRICTION AND WEAR OF COPPER-IMPREGNATED METALLIZED CARBON

研究了电流及其极性对浸铜碳滑板摩擦磨损性能的影响.利用SEM观察浸铜碳滑板磨损表面的形貌.结果表明,施加电流显著增加浸铜碳滑板的磨损量,但降低摩擦系数.浸铜碳滑板为正极时的磨损量比其为负极时的大,而2种极性条件下的摩擦系数相近;电流越大,磨损表面损伤越严重;正极磨损表面的氧化比负极剧烈.磨损机理主要为磨粒磨损、黏着磨损和电弧烧蚀.

Copper-impregnated metallized carbon has been widely used in maglev vehicles and high-speed railway trains due to its excellent electrical conductivity and high mechanical strength. The wear of copper-impregnated metallized carbon has aroused wide concern.To decrease the cost of maintenance and keep trains running safely,a better understanding of the wear mechanisms is needed. In this work.the effects of electrical current and its polarity on sliding friction and wear of copper impregnated metallized carbon against Cr Zr-Cu alloy rings were studied on UMT 2 tribometer with a brush-on-ring configuration.SEM and EDS were used to observe the morphologies of the worn surfaces and analyze the compositions of worn surfaces.The results showed that the wear mass loss increased with the rising of electrical current,the friction coefficient with electrical current was lower than that without electrical current.The wear mass losses of positive brush specimens wore higher than those of negative brush specimens.It was found that the surface damage of the worn surface of brush specimens became more serious with greater electrical current,the positive brush specimen suffered a heavier oxidation than that of negative brush specimen.Abrasive wear,adhesive wear and arc erosion were the dominant mechanisms during the electrical sliding process.