Phase diagram, thermodynamic modeling and predictions of glass-forming range and ability in the Co–Cu–Zr system

Several alloys were prepared and examined for microstructural and compositional analyses to measure the phase equilibria at 1023 K. According to the available experimental information, the Co–Cu–Zr system was thermodynamically modeled on the basis of the CALculation of PHAse Diagram (CALPHAD) method. Four disordered solutions liquid, A1, A2 and A3 were modeled as substitutional ones. A single function was employed to model the order-disorder transition from A2 to B2. The Laves phase Co ₂Zr was described in the regular form of (Co,Cu,Zr) ₂(Co,Cu,Zr) ₁, while the others with the remarkable solubility between Co and Cu were treated as a line compound. A group of self-consistent thermodynamic parameters was obtained. With these thermodynamic parameters, the experimental phase equilibria and thermochemical data were described satisfactorily, and the glass-forming range and ability were evaluated. The prediction of glass-forming range combined with P _HSS can provide guidance for the design of Co–Cu–Zr-based metallic glasses.