高压技术对烧结NdFeB性能和微观结构的影响

Effects of High Pressure Process on the Microstructure and Performances of NdFeB Magnets

摘要:

采用高压和常规压制方式制备了烧结 (PrNd)33Al0.7Nb0.6Cu0.1B1.05Febal (质量分数) 永磁体，利用扫描电镜、金相显微镜和振动样品磁强计及维氏硬度计对比研究了两种压制方式对样品微观组织和性能的影响。结果发现：与常规压制方式制备样品相比，1.8 GPa压强成型制备样品的Hcj和(BH)max分别提高了133 kA.m-1和0.6 kJ.m-3；而3.6 GPa压强成型制备样品的Hcj和(BH)max分别提高了120.3 kA.m-1和3.2 kJ.m-3。高压样品的主相晶粒较细小，富稀土相分布均匀合理，但过高的压强将使其维氏硬度降低

Abstract:

The sintered permanent magnets of (PrNd)33Al0.7Nb0.6Cu0.1B1.05Febal (wt%) were prepared by the high pressure and conventional molding processes. The performances and microstructure were discussed by metalloscope, VSM, SEM and so on. The results show that the Hcj and (BH)max of the samples by high pressure process (1.8 and 3.6 GPa) are much higher (133 kA·m-1 and 0.6 kJ·m-3; 120.3 kA·m-1 and 3.2 kJ·m-3) than those by the conventional pressure process. On the other hand, the former crystalline grains of NdFeB phase are thin and small. In addition, the former Nd-rich phases are homogeneous and reasonable, but too high pressure will decrease Vickers hardness of samples