采用声化学法制备Nd-Fe-B/α-Fe型双相包覆磁粉,再经放电等离子烧结(SPS)制备成致密块状磁体.研究了不同α-Fe包覆含量对复合磁体磁性能及微观结构的影响.结果表明,声化学法可以制备均匀混和的双相纳米磁粉,α-Fe纳米粉均匀的包覆在硬磁相颗粒周围.烧结后的各向同性磁体有明显的剩磁增强,具有较高的磁性能.当α-Fe包覆量为2%(体积分数)时,磁体性能最佳,其(BH)max值为148.64kJ/m^3.
Nd-Fe-B/α-Fe two-phase magnetic powders were obtained by sonochemistry method. Bulk Nd-Fe-B/α-Fe nanocomposite magnets were created successfully by hot pressing the powders using SPS. Effect of α-Fe content on magnetic properties and microstructure of the nanocomposite magnets was studied. Nano-sized α-Fe coating NdFeB two-phase powders were obtained by sonochemistry method; the two phases mixed homogeneously. The Nd-Fe-B/α-Fe magnets showed remanence enhancement and high magnetic properties after SPS hot press. Under optimum α-Fe content (2 vol %), bulk NdFeB/α-Fe possessed (BH)max= 148.64kJ/m^3.