Gibbs free energy difference in metallic glass forming liquids

Abstract

Expressions of Gibbs free energy difference (Δ G) based on linear variation of heat capacity difference of liquid and solid ( Δ C p l - s ) with temperature in the super-cooled metallic liquid is reviewed. Attractively, hyperbolic variation of Δ C p l - s with temperature is suggested from the experimental data. According to this hyperbolic relationship, Δ G expression of Thompson and Spaepen could be also derived and a new Δ G expression is proposed. Calculations with the present expression have shown that Δ G values obtained from six glass forming alloys (La 50Al 30Ni 20, Pd 40Ni 40P 20, Zr 52.5Cu 17.9Ni 14.6Al 10Ti 5, Zr 41.2Ti 13.8Cu 12.5Ni 10Be 22.5, Cu 47Ti 34Zr 11Ni 8 and Mg 65Cu 25Y 10) are consistent with experimental data. As compared with other Δ G expressions, deviations of the values calculated by the present expression from experimental data show the best stable at different reduced glass transition temperature ( T rg = T g/ T m) of amorphous alloys.