Limiting design parameters for future high speed, high current density sliding electrical contacts

Summary form only given. Most sliding contact designs are limited by a combination of electrical heating and sliding friction which produces an intense heat release in the small volume at the brush-rotor interface, thereby reaching upper temperature limits of concurrently available materials in a short time. As the brush temperature increases, wear increases rapidly while brush performance deteriorates. The authors describe a new consolidation method now being developed that uses an electrical high-energy/high-rate consolidation process for the manufacture of such high-temperature tribological materials. For copper-graphite, the high-current consolidation process induces local melting of the copper powder, resulting in a very high degree of geometrical conformability. At the same time, the short holding time at high temperature reduces the problems of oxidation at the copper-graphite interface.<>