【摘要】 利用透射电镜、X射线衍射仪、X射线能谱仪,对爆炸压结Nd-Fe-B永磁合金进行微观组织结构的观察和分析。结果表明:爆炸压结Nd-Fe-B的组织主要由基体Nd2Fe14B相、富O相和富Nd相组成;基体相是硬磁相,四方晶体结构,其晶格常数为a=0.88nm和c=1.22nm;富O相形貌呈三角状或层状,分布在3个晶粒交隅处和两个晶粒交界处,其晶体结构均为面心立方(fcc),点阵常数a=0.559nm;富Nd相呈不同块状形貌,镶嵌在基体内或晶界上,其晶体结构为密排六方(hcp),晶格常数a=0.395nm和c=0.628nm;在富O相中O,Nd和Fe的含量(原子分数,下同)分别为45%~60%,20%~40%和10%~12%,块状富Nd相中则为80%~85%Nd和10%~15%O,同时还发现晶界相中分布着少量的位错。更多还原

【Abstract】 The microstructure of the explosively compacted Nd-Fe-B permanent magnets has been investigated by means of TEM and XRD. It is shown that there are three kinds of phases: matrix Nd2Fe14B, O-rich phases and Nd-rich phase with different structures and compositions in explosively compacted Nd-Fe-B permanent magnets. Matrix Nd2Fe14B is predominantly the hard Nd2Fe14B phase with lattice parameters of a=0.88 nm and c=1.22 nm. The O-rich phase presented at the two-grain boundaries and three-grain junctions, with fcc structures, and lattice parameter is a=0.559 nm. The O-rich phase belong to the compound Nd-Fe-O, and contents of O, Nd and Fe are 56at%, 22at% and 21at%, respectively. It is also shown that a large number of the block-shaped Nd-rich phases are in the two-grain boundary or three-grain junctions or Nd2Fe14B phases, with hcp structure and lattice parameters of a=0.395 nm and c=0.628 nm. The Nd-rich phases belong to compound Nd-O, and contents of Nd and O are 85at% and 12at%, respectively. Also a few dislocations in the boundary phases have been observed.更多还原