晶界扩散低重稀土合金Pr-(Dy/Y)-Al对烧结Nd-Fe-B磁性能与微观结构的影响OA

In order to reduce the cost of diffusion sources,the effects of three low-cost diffusion sources,Pr70Dy10Al20,Pr70Y10Al20 and Pr60Dy10Y10Al20 on the magnetic properties and microstructure of sintered Nd-Fe-B magnets were investigated using grain boundary diffusion technology.After diffusion,the coercivity of the three magnets increased from 858 kA/m to 1 746 kA/m,1 118 kA/m and 1 572 kA/m,respectively.The Pr70Dy10Al20 magnet exhibited the largest coercivity enhancement,reaching 203%of the original magnet.This was primarily attributed to the formation of a Dy-rich shell and a continuous rare-earth-rich grain boundary phase.In the Pr70Y10Al20 diffused magnet,Y-rich shells with darker atomic number contrast were formed,and the diffusion depth of Y was similar to that of Dy in the Pr70Dy10Al20 diffused magnet.Although the coercivity increase in the Pr60Dy10Y10Al20 diffused magnet was lower than that in the Pr70Dy10Al20 diffused magnet,it still showed a significant improvement compared to the Pr70Y10Al20 diffused magnet.Microstructural analysis revealed that in the Pr60Dy10Y10Al20 diffused magnet,Pr,Dy,and Y tended to enter the main phase,forming thicker Pr-Y-Dy-rich shells,which reduced the anisotropy of the shells and limited the improvement of coercivity.