Estimation of Gibbs free energy difference in bulk metallic glass forming alloys

A newly derived expression for the Gibbs free energy difference (ΔG) between the crystalline and undercooled liquid phases of metallic glass-forming alloys has been utilized to obtain ΔG for a variety of systems viz. Al–La–Ni, Ni–Pd–P and Pd–Cu–Ni–P. It gives fairly good results for the first two, whereas it does not hold for the third one i.e. Pd40Cu30Ni10P20, which has been reported to possess exceptionally high glass-forming ability. In light of this, the expression of Thompson and Spaepen is modified to account for the ΔG of this system. The Gibbs free energy difference has been observed to be smallest for this glass in the entire undercooling range. The incorporation of Cu in the ternary Ni–Pd–P system increases the glass-forming ability.