晶界扩散Pr和Cu对烧结钕铁硼永磁体性能的影响

Effect of grain boundary diffusion Pr and Cu on properties of sintered Nd-Fe-B permanent magnet

利用磁控溅射镀膜技术,在烧结钕铁硼磁体表面分别沉积Pr、Cu及Pr_(75)Cu_(25)镀层,并对其进行晶界扩散热处理。分析了扩散前后磁体的磁性能、微观结构、温度稳定性和抗弯强度。与空白磁体相比,扩散磁体晶界富Nd相及其连续性明显增多、增强,隔离了主相晶粒,磁去耦作用较强,扩散Pr、Pr_(75)Cu_(25)磁体内禀矫顽力由12.86 kOe分别提升至14.69 kOe、15.78 kOe,扩散Cu磁体内禀矫顽力由13.38 kOe提升至14.83 kOe。在20~120℃范围内,扩散Pr、Cu、Pr_(75)Cu_(25)磁体的矫顽力温度系数|β|分别降低了0.034%/℃、0.021%/℃、0.089%/℃,磁通不可逆损失分别下降了20.96%、0.94%、27.71%,平均抗弯强度分别增高了55.89 MPa、149.00 MPa和130.21 MPa。

The Pr,Cu and Pr_(75)Cu_(25) were deposited on the sintered NdFeB by magnetron sputtering technology,and the samples were subjected to grain boundary diffusion heat treatment.The magnetic properties,microstructure,temperature stability and bending strength of the magnet were analyzed.Compared with the blank magnet,the grain boundary of the diffusion magnet has increased and enhanced the Nd phase and its continuity,isolated the main phase grain,and the magnetic decoupling effect is stronger.The coercivity of Pr and Pr_(75)Cu_(25) diffusion magnets increased from 12.86 kOe to 14.69 kOe and 15.78 kOe,respectively,and the coercivity in the diffusion Cu magnet is increased from 13.38 kOe to 14.83 kOe.In the temperature range of 20 to 120℃,the |β| of diffusion Pr,Cu and Pr_(75)Cu_(25) magnets decreases by 0.034%/℃,0.021%/℃and 0.089%/℃,respectively.The Hirr decreases by 20.96%,0.94% and 27.71%,respectively.The average bending strength increases by 55.89 MPa,149.00 MPa and 130.21 MPa,respectively.