Amorphous forming ranges of Al-Fe-Nd-Zr system predicted by Miedema and geometrical models

A method based on the semi-empirical Miedema model and a geometrical model was used to study the glass forming abilities (GFA) and the amorphous forming ranges of Al-Fe-Nd-Zr system and its constituent ternary systems. The amorphous forming composition ranges were analyzed based on different criteria such as Delta G(am-ss) and P-HSS (P-HSS=Delta IIchem (Delta S-C/R)(Delta S-sigma/R)) for Al-Fe-Nd system. The predicted amorphous forming range was in good agreement with the experimental results. The results showed that the criterion of Delta G(am-ss) was more accurate, and agreed well with the experiment results. The Gibbs free energy difference Delta G(am-ss) and parameter PHSS were then used to predict the amorphous forming composition range for the rest of the constitutive ternary systems of Al-Fe-Nd-Zr. In addition, the amorphous forming composition ranges of the (Al-Fe-Zr)(100-x) Nd-x (x=50, 60, 70) systems were predicted by Delta G(am-ss) and the modified parameter PHSS. The Gibbs free energy of Al-10(Fe1- xZrx)(30)Nd-60 were also calculated. The GFA parameter PHSS indicated that the composition with the highest GFA was Al33.5Fe13.5Zr3Nd50 for the (Al-Fe-Zr)(50)Nd-50 system, Al28.8Fe10Zr1.2Nd60 for the (Al-Fe-Zr)(40)Nd-60 system and Al22.8Fe6.9Zr0.3Nd70 for the (Al-Fe-Zr)(30)Nd-70 system, and the results suggested that those alloys with high content of Al had higher GFA. The appropriate content of neodymium and zirconium resulted in the lower value of PHSS and increased the GFA obviously.