Influence of Pr on Magnetic Properties and Microstructure of Melt-Spun (Nd1-xPrx )10.5 (FeCoZr)83.5 B6 Alloy

The influence of Pr on thermal stability, microstructure, and magnetic properties of melt-spun (Nd1-xPrx)10.5(FeCoZr)83.5B6 (x =0,0. 2 , 0. 4 , 0. 6 , 0. 8, 1. 0) alloy was investigated. By sub-overquenching to get the mixture of amorphous and fine crystallites and post annealing under the optimum conditions, bonded magnets with the best magnetic properties were prepared. With the increase of Pr content, He; increases, but Br decreases. (BH) max of magnets bonded with 3. 25% (mass fraction) epoxy reaches the maximum of 70. 6 kJ m -3 at x =0.6 - 0. 8. Substitution of Pr for Nd causes the crystallization temperature and crystallization energy to decrease. This thermal stability difference results in that ( Nd0.2Pr0.8)10.5 (FeCoZr)83.5B6 alloy has a rougher and more inhomogeneous microstructure than that of ( Nd0.8 Pr0.2)10.5 (FeCoZr)83.5 B6 alloy, furthermore, leads to the decrease of B, with the increase of Pr content.