Thermodynamic analysis of the Al–Cu–Zr bulk metallic glass system

As an essential constitution of either Cu- or Zr-based bulk metallic glass alloys, the Al–Cu–Zr ternary system has aroused a great attention for decades. Since the three constituent binary systems, Al–Cu, Al–Zr and Cu–Zr, have been optimized previously, the focus of this work was only given to the Al–Cu–Zr ternary system. Based on the experimental enthalpies of mixing of ternary liquid and undercooled liquid alloys as well as the evaluated isothermal sections, the Al–Cu–Zr ternary system has been assessed using the CALPHAD method. Most of the calculated results show good agreement with the experimental thermodynamic data and the reported phase diagrams. By employing the driving force criterion with the present thermodynamic description, the observed glass-forming abilities in the Al–Cu–Zr system can be accounted for satisfactorily.