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 ΔGam-ss and PHSS (PHSS=ΔHchem (ΔSC/R)(ΔSs/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 ΔGam-ss was more accurate, and agreed well with the experiment results. The Gibbs free energy difference ΔGam-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-xNdx (x=50, 60, 70) systems were predicted by ΔGam-ss and the modified parameter PHSS. The Gibbs free energy of Al10(Fe1−xZrx)30Nd60 were also calculated. The GFA parameter PHSS indicated that the composition with the highest GFA was Al33.5Fe13.5Zr3Nd50 for the (Al-Fe-Zr)50Nd50 system, Al28.8Fe10Zr1.2Nd60 for the (Al-Fe-Zr)40Nd60 system and Al22.8Fe6.9Zr0.3Nd70 for the (Al-Fe-Zr)30Nd70 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.

Amorphous forming ranges obtained by different methods for Al-Fe-Nd (The isometric contours indicate the calculated results of PHSS (kJ/mol), the contour maps indicate the results of ΔGam-ss (kJ/mol))Figure optionsDownload as PowerPoint slide