Phase Structure Evolution and Magnetic Properties of Nd₂Fe₁₄B/α‐Fe Hot‐Deformed Magnets With α‐Fe Content Variation

Dual‐phase composite magnetic materials represent a novel class of magnetic systems formed through exchange coupling between soft and hard magnetic phases. These materials combine the high remanence of hard magnetic phases with the low coercivity of soft magnetic phases, enabling rapid functional switching with minimal energy loss. This makes them promising candidates for power equipment. In this work, Nd 2 Fe 14 B/α‐Fe dual‐phase magnets were prepared using a hot‐pressing and hot‐deforming process on mixed powders. The effect of α‐Fe content (10–60 wt.%) on the phase structure and magnetic properties was investigated. Increasing α‐Fe content enhances the saturation magnetic polarization ( J s ) from 1.48 to 1.77 T, but reduces remanence ( J r ) from 1.28 to 0.73 T and coercivity ( H c ) from 133.35 to 13.51 kA/m, attributing to the breakdown of exchange coupling mechanisms under excessive soft‐phase fractions. Magnets with 40–50 wt.% α‐Fe exhibit excellent high‐temperature (400 K) properties, maintaining J r ≥ 0.80 T and H c ≤ 26.82 kA/m. Furthermore, these magnets demonstrate a low remanence temperature coefficient (−0.19%/K to −0.25%/K) and retain hardness above 50 HRC. This work achieves synergistic optimization of magnetic properties, thermal stability and mechanical performance, providing valuable supports for developing the dual‐phase composite magnetic materials with high J r and low H c for power equipment.