Phase equilibria of the Al-Cu-Zn system for compositions close to brass alloys

The effect of aluminium on the equilibrium phases of the Cu-Zn alloys has been studied within the range of chemical compositions of interest to brass producers. Ternary alloys were cast by melting two Cu-Zn base alloys (with ∼59.5% and ∼61.2 wt.% Cu) followed by the addition of aluminium up to 3.68 wt.%. Isothermal homogenization, followed by rapid cooling, has been used to determine the equilibrium phases at different temperatures. The alloys have been observed by scanning electron microscopy (SEM) and the respective chemical analysis determined by electron probe microanalysis (EPMA). Statistical analysis of the results enables a correlation of the chemical compositions of the equilibrium phases with temperature within composition range of the study.