Nd-Dy-Fe-Nb-Al-B合金铸锭组织和烧结组织的研究

Ingots and sintered microstructures of Nd-Dy-Fe-Nb-Al-B alloy

采用扫描电子显微镜、能谱分析及烧结体磁性能的测量,研究了Nd-Dy-Fe-Nb-Al-B合金的铸锭组织和烧结组织。结果表明,铸锭组织从接触水冷模的表面到铸锭中心,晶粒逐渐粗化,而且在铸锭中心存在大量α-Fe,Al元素稍微富集于主相晶粒间的富钕相中;在烧结组织中,发现规则的富Nb相(Nb∶Fe=1∶1),有利于烧结体晶粒的细化,同时存在稀土含量具有很大差异的两种富钕相和一些粒状富B相。烧结磁体的磁性能为Br=1.229T,Hcj=1024kA/m,(BH)max=280kJ/m3。

Ingots and sintered microstructures of Nd-Dy-Fe-Nb-Al-B alloy were investigated by SEM, energy spectrum analysis and magnetic property measurement. The results show that, for the ingots, the grains are coarsened gradually from the surface contacted with water-cooled mold to the center of ingots where a large mount of α-Fe exists, Al element is enriched in the Nd-rich phase slightly. Nb-rich phase with Nb： Fe = 1 ： 1 is formed in the sintered bodies which is beneficial to refine the grains. Two types of Nd-rich phases with different compositions and B-rich phase with granular shape also exist. The magnetic properties of sintered magnets are Br = 1. 229T,Hcj = 1024kA/m, （BH） max = 280kJ/m^3.