Bulk Metallic Glass Formation, Composite, And Magnetic Properties Of Fe-b-nd Based Alloys

摘要

The glass formation in Fe-rich ternary Fe-B-Nd and quaternary (Fe,B,Nd)_(96)Nb_4 alloys has been studied and the best ternary and quaternary glass formers are located at Fe_(67)B_(23)Nd_(10) and (Fe_(68)B_(25)Nd_7)Nb_4 with critical diameters of 1 and 4 mm, respectively. For (Fe,B,Nd)_(96)Nb_4 alloys, the competing phases with glass were identified by monitoring the microstructure change. Fe_(14)Nd_2B was discovered to be one competing phase, which is the principle magnetic phase for Nd-Fe-B hard magnets. Composites with uniformly distributed Fe_(14)Nd_2B were formed for quaternary alloys with a diameter of 1.5 to 3 mm. Bulk hard magnets could be obtained by directly annealing the composites in a compositional area. A hard magnet with a coercivity of 1,100 kAm~(-1) and a maximum energy product, (BH)_(max), of 33 kJm~(-3) was obtained at (Fe_(67)B_(23)Nd_(10))_(96)Nb_4 by annealing. The combination of hard magnetic properties and the large critical sample size may make these alloys a commercially viable candidate for industrial applications.