Effect of Mn on microstructure and properties of Cu-12Al powder metallurgy alloy

Abstract

Cu-12Al-xMn (x = 0, 1, 2, 3, 4%, mass fraction) alloys were produced using powder metallurgy to investigate the effect of Mn content on the alloy's microstructure and mechanical properties. The Cu-12Al (no Mn) and Cu-12Al-1Mn (1 wt% Mn) alloys consisted of the α + γ phases, where the size of the α grains in the Cu-12Al-1Mn alloy are much larger. Mn effectively inhibited the eutectoid transformation at a concentration above 1 wt%. Furthermore, the β phase was converted to the β′-martensite phase, which had a monoclinic structure after slow cooling. The phases of the alloy changed from the α + γ phases to the α + β′ + γ phases with the further addition of Mn, and the tensile strength of the 3 wt% Mn alloy was 380.59 MPa. The addition of Mn did not have a significant effect on the density of the alloy.