制备了复合添加0.8%(原子分数)Nb+0.9%(原子分数)Zr和复合添加1.5%(原子分数)Nb+1.2%(原子分数)Zr的两种粉末烧结Nd(Dy,Gd)Fe(Nb,Zr,Al,Cu)B永磁体,通过对它们的微观结构、微区成分以及磁性能的分析,研究了Nb、Zr添加量对磁体晶界相形成的影响以及晶界新相与磁体矫顽力之间的关系。结果表明,在复合添加0.8%(原子分数)Nb+0.9%(原子分数)Zr的磁体中,Nb、Zr元素使部分晶界富稀土相合金化,形成灰色的新相,相应地磁体的矫顽力达到1900kA/m;在复合添加1.5%(原子分数)Nb+1.2%(原子分数)Zr的磁体中,除晶界上形成了含Nb、Zr元素的合金化富稀土相之外,还形成了直径约2μm的圆形或多边形块状NbFe化合物新相,使磁体的矫顽力进一步跃升到2229.30kA/m。
Nd(Dy,Gd)-Fe(Nb,Zr,Al,Cu)-B powder sintered magnets with 0.8at%Nb+0.9at%Zr or 1.5at%Nb+1.2at%Zr were prepared.The effects of Nb and Zr dopant content on the formation of intergranular phases and the relationship between the intergranular new phases and the coercivity have been investigated on the analysis basis of microstructures,micro-area compositions and magnetic properties of the magnets.The results show that,in the magnets with 0.8at%Nb+0.9at%Zr,a new grey boundary phase with high content of Nb and Zr elements is formed,accordingly the intrinsic coercive force of the magnets is 1900kA/m.And in the magnets with 1.5at%Nb and 1.2at%Zr,in addition to the new grey boundary phase,a new kind of block NbFe phase with round or polygonal morphology,about 2μm,appear in magnet boundaries.This makes the intrinsic coercive force of the magnets further increases to 2229.3kA/m.