2014 Volume 55 Issue 3 Pages 528-533
In this study, the microstructure and mechanical properties of Cu–40Zn brass alloy with 0.5 mass% Cr additives produced by powder metallurgy (P/M) process were investigated. Cu–40Zn–0.5Cr and Cu–40Zn brass powders were made by water-atomization process, and used as raw materials. These powders were consolidated by hot extrusion at various temperatures by considering the precipitation behavior of β phase and Cr. Yield stress of Cu–40Zn–0.5Cr extruded at 773 K was 514.6 MPa, while that of the monolithic Cu–40Zn extruded at the same temperature was 332.6 MPa. Solid solution of chromium in the Cu–40Zn–0.5Cr brass alloy extruded at 773 K was about twice as that of the same brass alloy extruded at 873 K. The strength impact of Cr solid solution was much effective compared to Cr precipitation strengthening. The ratio of solid solution strengthening by chromium additive was 130 MPa/mass%[Cr]. The grain size of extruded materials increased with increasing the extrusion temperature.