化学气相沉积法制备Nd-Fe-B/α-Fe纳米复合磁体

Preparation of Nd-Fe-B/α-Fe Nano-Composite Magnets by Chemical Vapor Deposition

摘要:

采用化学气相沉积法制备单质铁包覆Nd-Fe-B复合磁粉, 经放电等离子烧结得到Nd-Fe-B/α-Fe纳米复合磁体。SEM、XRD、XPS研究表明：采用化学气相沉积法可以实现纳米单质铁对Nd-Fe-B磁粉表面的均匀包覆，有效地改善软硬磁性相的分布，提高磁体的综合磁性能。化学气相沉积温度为120 ℃、沉积时间为30 min时，得到的包覆层致密均匀，单质铁颗粒尺寸50~100 nm。在优化工艺条件下制备出接近全致密的纳米复合磁体，其磁性能可达：Br=0.81 T, Hcj=1286 kA/m , (BH)m =108.6 kJ/m3

Abstract:

α-Fe coated Nd-Fe-B nano-composite magnetic powders were prepared by chemical vapor deposition (CVD), which were then spark plasma sintered to obtain Nd-Fe-B/α-Fe nano-composite magnets. SEM, XRD and XPS researches show that CVD method can realize uniform coating of Nd-Fe-B powders with α-Fe, improve effectively the distribution of hard and soft magnetic properties, and increase the integrated magnetic properties of the magnets. The obtained coating was dense and uniform, and the particle size of α-Fe was about 50-100 nm, when the temperature of CVD was 120 oC and the time was 30 min. Under optimum processing conditions, the SPSed NdFeB magnet can be nearly fully dense and reach the best magnetic properties with Br of 0.81 T, Hcj of 1286 kA/ m and (BH)m of 108.6 kJ/m3