铜石墨合金材料在载流条件下的摩擦磨损行为研究

Friction and Wear Behavior of Copper-graphite Material under Electrical Current

采用冷压烧结粉末冶金法,以300 MPa的压力进行初压,在氢气保护气氛下于烧结温度为950℃,3 h下烧结,然后冷却至室温后再以300 MPa的压力进行复压制备出铜石墨合金材料.通过电滑动磨损试验及扫描电子显微镜分析等方法研究了铜石墨合金材料的磨损性能,探讨其磨损机制.结果表明:在试验参数范围内,试样的磨损量随着试验载荷、速度及电流密度的增加而增大;在载流条件下电流产生的电弧热是其磨损量增加的主要因素;石墨和铅以单质形式存在有利于摩擦副之间的润滑和提高其耐磨性能;合金的磨损机制主要为磨粒磨损、电侵蚀磨损和黏着磨损.

Sliding wear behavior of copper-graphite composite for maglev vehicles and high-speed railway train was nvestigated. The samples were formed by cold pressing at 300 MPa and by hot sintering （950℃ × 3 h） in a hydrogen atmosphere. After specimens were cooled to room temperature with the furnace, further pressing at 300 MPa was performed. Wear tests were conducted with a specially designed sliding apparatus to simulate the tribological condition of sliding current collectors in a maglev system. The material was slid against a stainless steel band under unlubricated condition. Worn surfaces of the material were analyzed by SEM and field-emission-gun environment SEM equipped with an energy dispersive X-ray spectroscopy. Within the studied range of normal pressure and electrical current, wear loss increased with increasing normal pressure and electrical current. Adhesive wear, abrasive wear and arc erosion were the dominant mechanisms during electrical sliding. It provides principle for designing suitable sliding counter parts for the current collection device in maglev system.