Model copper-matrix MMCs reinforced by high manganese steel particles have been characterized for mechanical strength and conductivity in comparison to commercially available current collection material. The commercial material is intended for current collection while sliding over a copper trolley. As shown, solid phase sintering allows obtaining composites of high bulk strength. Friction coefficient and wear rate of so obtained composites in sliding over steel counterbody while passing alternating electric current have been determined. It was found that high-manganese steel facilitates the formation of so-called secondary structures on the sliding surfaces. These structures consist of mixed oxides, which increase the sliding contact resistance. Most intense oxidizing occurs at current density 50 A/cm2. The results of comparison carried out between the model and commercially available materials show that model MMC has somewhat higher electrical resistance at current densities above 25 A/cm2. However, the wear rate of the model material in the absence of intense oxidation is lower than that of commercial one. To complete the picture, we determined also the wear rate of carbon graphite material under the same experimental conditions. As shown, carbon graphite fails to pass the current of densities above 25 A/cm2.
|Состояние||Опубликовано - 2005|
ASJC Scopus subject areas
- Engineering (miscellaneous)
- Physics and Astronomy (miscellaneous)