【摘要】 对添加 Nb的 Nd- Fe- B铸态合金的结晶状态、磁体的显微组织形貌、磁性能等进行了详细研究。研究发现 :添加 Nb使 Nd- Fe- B铸态合金的片状晶尺寸明显变小 ,Nd- Fe- B磁粉的抗氧化性能提高 ,磁体的晶粒结构均匀一致 ,不含 Nb的 Nd- Fe- B磁体晶粒的大小、形状差异非常大 ,其显微组织呈现出一种类似“团窝”状的结构。这种结构使 Nd- Fe- B磁体的磁性能恶化。添加一定量的 Nb元素后 ,这种“团窝”状结构消失 ,磁体的晶粒更加规则 ,组织结构更加均匀。采用常规的湿法制粉工艺 ,用 Nb含量 (摩尔分数 )为 0 .44%的 Nd- Fe- B合金得到了 ( BH ) max 为336k J/ m3( 4 2 .1 MGOe)的烧结磁体 ,而相同成分的不含 Nb磁体的最大磁能积只有 1 94k J/ m3。更多还原

【Abstract】 In this work the effect of Nb addition on the microstructures of Nd Fe B as cast alloys and the magnetic properties of anisotropic Nd Fe B sintered magnets were investigated in detail. Experiments revealed that the size of the plate like grains of Nd Fe B as cast alloys could be drastically decreased and the grain shape of the sintered magnets could be markedly regularized by Nb addition, and thus the magnetic properties of the magnets were improved. As a result, magnet with the magnetic property of (BH) max =336kJ/m 3(42.1MGOe) was obtained by conventional wet process with 0.44at%Nb containing alloy.更多还原