Glass formation and magnetic properties of ternary Fe-B-Y/Nd and quaternary Fe-B-Nd-Nb alloys

Abstract

Glass forming ability(GFA) of Fe-rich ternary Fe-B-Y/Nd alloys was studied and the best glass formers were located respectively. Mechanism of Y in improving the GFA was discussed. Strong dependence of GFA on Y/Nd content was observed. GFA of Fe-rich quaternary Fe-B-Nd-Nb alloys was investigated and the best glass former with a critical diameter of 4 mm was located. Efficient cluster packing model to predict the best glass former was discussed and a modification was proposed. By the modified ECP model, the predictions were in a much better agreement with the best glass formers located experimentally in Fe-B-Y/Nd and Fe-B-Nd-Nb systems. Bulk glassy Fe-B-Nd-Nb composites with principal hard magnetic phase Fe14Nd2B were synthesized. After annealing, bulk hard magnets were obtained. A compositional range for bulk magnets formation was defined. The combination of hard magnetic properties and the largest critical diameter may make Fe-B-Nd-Nb a good candidate for industrial applications.