Nanocrystalline Nd-Fe-B Alloys for Polymer-Bonded Magnets Production

Abstract

This study presents how different nanostructures of starting Nd-Fe-B particles have influence on magnetic properties of polymer-bonded Nd-Fe-B materials. Two types of nanocrystalline Nd-Fe-B alloys were used for polymer composite production by compression molding technique. The particles with low neodymium content (Nd-low) have nanocomposite structure with small exchange coupling effect between hard and soft magnetic phase. In other hand, practically monophase hard magnetic structure of Nd-Fe-B particles with stoichiometric neodymium content (Nd-stoich) shows improved magnetic properties. With increasing concentration of polymer matrix, the coercivity (Hcb), remanence (Br), and maximum energy product ((BH)max) decrease more prominenty for composites with stoichiometric Nd-Fe-B content.

Magneto-Mechanical and Thermal Properties of Nd-Fe-B-Epoxy-Bonded Composite Materials

“…In alignment with previous research activities [14,17,[37][38][39], this study demonstrates the effect of varying the Nd-Fe-B weight fraction on magnetic behavior, microstructure, thermal properties and impact toughness, as well as on the fatigue crack propagation of PBMs. A correlation between these properties has been developed and presented in this work for composites with various weight ratios of Nd-Fe-B to epoxy resin.…”

“…Stoichiometric Nd-Fe-B alloy was applied as magnetic filler for polymer composite materials production. The magnetic test, conducted on a 0.461 cm 2 , sample gives: (BH) max = 104.1 kJ/m 3 , H cb = 480 kA/m, H cj = 694 kA/m, B r = 0.818 T. Moreover, the chemical composition is as follows: Nd (21-25 wt.%), Co (5 wt.%), Zr (3-5 wt.%), B (1.5 wt.%) and Fe (balance) [38]. A SEM image of used particles and the respective particle size histogram are presented in Figure 1a,b.…”