Dependence of microstructure and mechanical properties on hot-extrusion temperatures of the developed high-strength Cu40Zn-CrFeTiSn brass by powder metallurgy

Effect of extrusion temperature on the microstructure and mechanical properties of the powder metallurgy Cu40Zn-CrFeTiSn alloy were investigated, through analysis on the solid solution of alloying elements, phase transformation and precipitation behavior. The extrusion was carried out between 500 °C and 650 °C using an extrusion ratio of 37:1. After extrusion, the microstructure was found consisting of the dual α+β phase structure and precipitates dispersing uniformly in the matrix. The tensile strength gradually decreased when the extrusion preheating temperature was increased. Solid solubility of Ti and Cr decreased steadily and grain coarsening occurred with increase in the extrusion temperature. Consequently, the lower extrusion preheating temperature was necessary to obtain excellent final mechanical properties, thus the extrusion temperature of 500 °C was enough to produce good ductility while maintaining the promising values of mechanical properties after extrusion.