(Pr,Nd)–Fe–B nanocrystalline magnetic materials with TiC additions

Abstract

The effect of titanium carbide (TiC) addition and Pr substitution in nanocrystalline Nd-Fe-B based magnetic materials has been investigated. Rapidly solidified (Pr,Nd)-Fe-B alloys were prepared by melt spinning. The compositions studied were (PrxNd1−x)9.5Fe84.5B6 (x=0, 0.1, 0.25, 0.5, 0.75, and 1) with the addition of 3at.% TiC. Varying the wheel speed from 15to30m∕s, the best magnetic properties were found for samples prepared at 20m∕s. All samples were nanocrystalline in the as-cast state. The average coercive field ranged from 10.0to12.6kOe and energy product from 7.8to9.0MGOe. The improvement in the coercive field compared to similar Nd based alloys was about 30%. Rietveld analysis of x-ray data for the Pr9.5Fe84.5B6 sample revealed that this material consists of approximately 70wt.% of 2:14:1 phase and 30wt.% of α-Fe. This result was confirmed by Mössbauer data analysis and is in agreement with compositions expected from the ternary phase diagram.