Effect of stacking configurations on the magnetic properties and microstructures of hot-deformed Nd-Fe-B magnets

Nd-Fe-B permanent magnetic materials exhibit excellent coercivity and maximum energy product, making them indispensable key materials in fields such as new energy electric vehicles, humanoid robots, and advanced medical equipment. In this paper, hot-deformed magnets were prepared using Nd-La-Y-Fe-B magnetic powders and commercial Nd-Fe-B magnetic powders with different stacking configurations and the effect of stacking configurations on the magnetic properties, phase compositions, elemental distributions and microstructures of the hot-deformed magnets were explored. Blending Nd-La-Y-Fe-B and commercial Nd-Fe-B magnetic powders in a 1:1 ratio yields a dual-main-phase hot-deformed magnet with optimal performance, achieving a remanence of 13.06 kGs, a coercivity of 12.09 kOe, and a maximum energy product of 40.36 MGOe. Microstructural analysis indicates that the addition of Nd-Fe-B powders can compensate for the deficient rare-earth-rich phase in the Nd-La-Y-Fe-B powders. This results in a thick and continuously distributed grain boundary phase between the main phase grains, while reducing the agglomerated rare-earth-rich regions. Furthermore, stacking configurations show a significant influence on the magnetic performance. Positioning the magnetic powder with poor deformability in the middle region of the magnet enhances grain orientation within the powder, thereby effectively increasing remanence. • Rational stacking design can effectively improve the magnetic properties of magnets. • Positioning the magnetic powder with poor deformability in the middle region enhances grain orientation within the powder. • The MIX-magnet exhibited the optimal magnetic performance.