A criterion for the glass-forming ability of binary bulk metallic glasses

Abstract

We proposed a parameter ϕ=(ΔHmc−RΔTemix)/ΔHmc as a criterion for glass-forming ability (GFA) of binary alloys near eutectic composition using the thermodynamic data of the equilibrium phase diagram by considering the relative thermodynamic stability of the liquid phase. The larger φ is, the larger GFA is in different binary alloy systems. A linear fit of Rc=7.73×1023 exp(−65.26φ) is obtained, where Rc denotes the critical cooling rate to form glass from liquid. Since φ is determined directly from thermodynamic data of elements and well known equilibrium phase diagram, GFA of binary alloys can be easily estimated without any thermal measurement after fabrication of BMGs.