The effects of Nd-rich phase distribution on deformation ability of hydrogenation-disproportionation-desorption-recombination powders and magnetic properties of the final die-upset Nd-Fe-B magnets

摘要

Nano-crystalline and micron-crystalline Nd-Fe-B powders were employed to hydrogenation-disproportionation-desorption-recombination (HDDR) process to investigate the structural factors of deformation ability in HDDR powders. It was found that the deformation ability and magnetic properties of the final die-upset magnet were optimized significantly by nano-crystalline powders. Structure investigation shows that the variations in coercivity and deformation ability were attributed to the Nd-rich phase distribution in HDDR powders. Meanwhile, enhancement of remanence and squareness indicated the uniform distribution of Nd-rich phase and the narrow grain size distribution by using nano-sized crystalline powders were in favor of c-axis alignment of 2:14:1 phase.