Achieving Improved Strength and Ductility Through Multi-Pass Cold Deformation and Annealing of a Cu-Zn-Bi Alloy

Abstract

In this work, a simple-yet-powerful processing method was applied successfully to a Bi-containing brass alloy (Cu–30wt.%Zn–3wt.%Bi), which utilized multi-pass proper annealing following medium-strain cold-rolling deformation. Both strength and ductility of the alloy have been improved simultaneously. This is mainly due to the redistribution of the bulky Bi phase along the rolling plane as well as the grain refinement of the brass matrix. Bi phase pancaking reduces the possibility of cracking at the early stages during straining whilst grain size refines continuously cycle-by-cycle, and the matrix is strengthened. The processing method could be applied to other alloys with similar microstructure.

Keywords: Metals and alloys, Bi-containing brass, microstructure, Cold-rolling, Recrystallization