Phase equilibria of the Co-Cu-Zn system at 600 °C and 450 °C

The 600 °C and 450 °C isothermal sections of the Co-Cu-Zn ternary system have been investigated experimentally by means of scanning electron microscopy coupled with energy dispersive x-ray spectroscopy, and x-ray diffraction. Five three-phase regions were confirmed in the 600 °C isothermal section and six three-phase regions existed in the system at 450 °C. The γ-Co5Zn21 and Γ-Cu5Zn8 phases formed a continuous solid solution, which is designated as the γ/Γ phase. No ternary compound was found in the present work. The solubility of Co in δ and β is up to 1.8 and 8.8 at% respectively, and the maximum solubility of Cu in γ1 and β1 is 14.7 and 7.9 at% respectively at 600 °C. The maximum solubility of Co in ε and β ´ is 8.5 and 6.7 at% respectively, and the solubility of Cu in γ2, γ1 and β1 is up to 12.9, 14.4 and 11.2 at% respectively at 450 °C.