High-Energy Extrusion-Molded Nd-Fe-B Magnets

High-energy extrusion-molded magnets, composed of isotropic Nd-Fe-B powder and Nylon-12, were developed. The mechanical properties and packing factor of the extruded products were investigated. With proper adjustment of the magnetic powder distribution, the extruded products contained 78 vol% magnetic powder and had a (BH)max of 9.9 MGOe. The shearing strength of the extruded products was 7.83 kgf/mm², which is about 1.6 times that of compression-molded magnets with the same formulation. The porosity fraction in the extruded products was 1.1%, which is significantly less than in compression-molded magnets.