The evolution of microstructure and properties of Cu-Cr alloys synthesized via flake powder metallurgy assisted by mechanical alloying and hot pressing

Abstract

In the study, the effects of mechanical alloying (MA) time and Cr content (wt.%) on the microstructure, density and hardness, electrical conductivity and oxidation resistance of Cu-Cr alloys were investigated. Cu-Cr alloy powders containing 0.25, 0.5, 1 and 2 wt.%Cr powders were milled for 0.5, 1, 2, and 4 h in a planetary ball mill. Results showed that experimental density of pure copper sample was measured as 7.03 g/cm 3 . The highest density of 8.43 g/cm 3 was achieved for the Cu-Cr alloys with 0.5 wt.% Cr fabricated by 4 h of MA. The hardness of Cu-Cr alloys increased with increasing MA time and Cr content. The Cu-Cr sample containing 2 wt.% Cr showed highest hardness value of ~128 HB. Electrical conductivity of Cu-Cr alloys with 0.5 wt.% Cr fabricated by alloying for 4 h reached to the optimum of 91 IACS%. • Determining the effect of flake powder metallurgy on the properties of Cu-Cr alloys • Obtaining optimum material properties with 0.5%wt. Cr and 4 h mechanical alloying • 20% increase in density values compared to those of samples from initial Cu powders • 40% improvement in hardness by mechanical alloying time of 4 h • Reaching the electrical conductivity value of 91%IACS with the optimum samples