Thermodynamic prediction of bulk metallic glass forming alloys in ternary Zr–Cu–X (X = Ag, Al, Ti, Ga) systems

Abstract

Prediction of bulk metallic glass (BMG) forming compositions has always been a challenge due to thermodynamic and kinetic constraints. In the present investigation, a parameter based on the enthalpy of chemical mixing (∆ H chem) and the mismatch entropy (∆ S σ/ k B) has been used to correlate with glass forming ability in some Zr based BMGs. The new thermodynamic parameter, P HS = ∆ H chem × ∆ S σ/ k B, is found to have strong correlation with glass forming ability in the configurational entropy (∆ S config/ R) range of 0.9–1.0. P HS has been calculated for compositions in Zr–Cu–Ag, Zr–Cu–Al, Zr–Cu–Ti and Zr–Cu–Ga ternary systems. It is observed that in all the systems studied, the best BMG composition (highest critical diameter ( Z c) of glass formation) is the one that corresponds to the highest negative P HS value. Present approach using P HS could be road map to design new BMG forming compositions.