Revisiting the Phase Equilibria in the Cu-Zn Binary System

Phase equilibria were investigated between 200 and 800 degrees C in the Cu-Zn binary system. Wavelength dispersive spectroscopy (WDS) was performed to determine the equilibrium compositions, and differential scanning calorimetry (DSC) was performed to investigate the solidus and liquidus temperatures and the invariant reaction temperatures of the Zn-rich portion. The beta/(alpha + beta) boundary in the Cu-rich portion extended toward the Cu-rich side as the temperature decreased below the A2-B2 order-disorder transformation temperature, and the phase boundaries of the gamma, delta and epsilon phases shifted toward the Cu-rich side. The liquidus temperatures of the epsilon + liquid were higher than those of the previous report. From the experimental results, the phase diagram of the Cu-Zn binary system was determined in the whole composition range.