Production of copper based contact metarial by P/M and its properties

In this study, microstructures, electrical performance and some mechanical properties of copper-based composite contact materials, which were produced by mechanical alloying method, were investigated. Various oxides and sort of Carbons were added the copper powder at different proportions and then alloyed for 6 hours in a planetary ball mill. Mechanically alloyed powder mixtures contain active carbon and graphite at the wt. ratio of 0,25%, 0,5%, 0,75%, 1% and Al2O3, TiO2, Y2O3 at the wt. ratio of 1%, 5%, 10%. After alloying, these powders were pressed and sintered at 850 oC in argon-hydrogen atmosphere. Electrical conductivity tests were applied on these samples to determine the best conductivity. The results showed that 5% oxide, 0.25% activated carbon and graphite reinforced samples exhibited the best conductivity. In order to determine the contact performance of these samples, turn on /off tests were made by count of 1000, 3000 and 6000 cycles.