添加Dy和Dy_2O_3的烧结NdFeB系永磁体的显微结构与磁硬化

MICROSTRUCTURE AND MAGNETIC HARDENING OF SINTERED NdFeB MAGNETS DOPING Dy OR Dy_2O_3

研究了(Nd_(1-x)Dy_x)_(16)Fe_(77.2)B_(6.8)和Nd_(16)Fe_(77.2)B_(6.8)+ywt-% Dy_2O_3磁体的磁性能、显微结构和磁硬化,在冶炼时添加Dy,Dy原子进入基体相,使其H_A提高,并细化晶粒和改善边界结构,提高磁体的矫顽力H_c,在制粉时添加Dy_2O_3,Dy原子进入基体相晶粒的外延展,使其K_1~2提高,同样细化晶粒和改善边界结构,并减少外延层厚度,提高磁体的矫顽力H_(ci),添加约2—3Wt—%的Dy_2O_3可制造出高H_(ci)高磁能积(BH)_m的NdFeB系烧结永磁材料。

The magnetic properties, microstructure and magnetic hardening of sintered (Nd_(1-x)Dy_x)_(16)Fe_(77.2)B_(6.8)and Nd_(16)Fe_(77.2)B_(6.8)+y wt-% Dy_2O_3 magnets have been studied. As an addition of Dy metal to the magnet during smelting, Dy atoms may enter the matrix phase Nd_2Fe_(14)B, so as to enable enhance H_A, fine grains and improve boundary structure, as well as to increase H_(ci) of the magnet. If Dy_2O_3 added to powder material prior to sintering, Dy atoms diffuse into the epitaxial layer of grains of matrix phase causing enhancement of K_1~1, also refine- ment of grains and improvement of boundary structure. The NdFeB based permanent magnets with higher H_(ci) and greater (BH)_m may be produced by adding Dy_2O_3 about 2--3 wt--% which make a favourable condition for lower cost.