Mechanical-induced magnetic anisotropy in calendered bonded magnets recycled from hot-deformed magnets

It is difficult to efficiently manufacture anisotropic bonded magnets due to the technical difficulties of bonding under an external magnetic field. In addition, the preparation process cost of the anisotropic magnetic powder is also high. In this paper, the anisotropic bonded magnets recycled from waste heat-deformed Nd–Fe–B magnetic rings were investigated. Four types of waste magnetic rings were mechanically crushed in argon gas to obtain magnetic powders. The reprocessed magnetic powder exhibited strong magnetic anisotropy with 1% in remanence compared to the original magnetic ring. Regenerated bonded magnets were prepared using calendering processes without an external magnetic field. The results show that magnets prepared by calendering exhibit mechanically induced magnetic anisotropy and optimal performance, including remanence of 7.00 kG, coercivity of 17.83 kOe, and maximum energy product of 11.02 MGOe. This study provides a new approach for the efficient regeneration of scrap Nd–Fe–B magnetic rings.