Dispersion hardened Cu-Al2O3 produced by high energy milling

Abstract

Prealloyed copper powders containing different amounts of aluminum (Cu-1w/oAl, Cu-2.5w/oAl and Cu-3.5w/oAl) were processed in a planetary ball mill to evaluate matrix hardening due to the formation of the formation of Al2O3 particles in situ by internal oxidation, Following milling, the powders, were treated in hydrogen at 400 degreesC for 1h to eliminate oxide formed on the powder surfaces during milling. Compacts were obtained hot pressing in argon at 800 degreesC for 3h under a pressure of 35MPa. The copper matrix hardening was estimated by means of microhardness measurements. The prealloyed Cu-3.5w/oAl powder showed the most pronounced hardening. After 5h of milling the microhardness of the prealloyed compacts is 3 to 4 times higher than that of electrolytic copper compact under identical conditions.