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 ΔG^am-ss and P_HSS (P_HSS=ΔH^chem (ΔS_C/R)(ΔS_s/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 ΔG^am-ss was more accurate, and agreed well with the experiment results. The Gibbs free energy difference ΔG^am-ss and parameter P_HSS 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-xNd_x (x=50, 60, 70) systems were predicted by ΔG^am-ss and the modified parameter P_HSS. The Gibbs free energy of Al₁₀(Fe_1?xZr_x)₃₀Nd₆₀ were also calculated. The GFA parameter P_HSS indicated that the composition with the highest GFA was Al_33.5Fe_13.5Zr₃Nd₅₀ for the (Al-Fe-Zr)₅₀Nd₅₀ system, Al_28.8Fe₁₀Zr_1.2Nd₆₀ for the (Al-Fe-Zr)₄₀Nd₆₀ system and Al_22.8Fe_6.9Zr_0.3Nd₇₀ 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 P_HSS and increased the GFA obviously.