Gibbs Free Energy Difference in Bulk Metallic Glass Forming Alloys

摘要

The Gibbs Free Energy Difference between the solid and liquid phases (ΔG) is related to nucleation frequency and has played an important role in predicting the glass forming ability (GFA) of multicomponent metallic alloys. This is due to the fact that the maximum energy for nucleus formation i.e. the activation barrier for nucleation has an inverse square relation with ΔG.The Gibbs Free Energy Difference of three multi-component bulk metallic glasses namely Mg_(65)Cu_(25)Y_(10), Zr_(57)Cu_(15.4)Ni_(12.6)Al_(10)Nb_5 and Zr_(52.5)Cu_(17.9)Ni_(14.6)Al_(10)Ti_5 have been evaluated using two new expressions. The results show that the AG values calculated assuming AC to be constant lie closer to the experimental values for the Mg based system while in the case of two Zr based systems, ΔG computed using the hyperbolic variation of ΔC_p show improved agreement with the experimental data.