Ce取代量对烧结NdFeB磁体微观结构和性能的影响

Effects of Ce substitution amount on microstructure and properties of sintered NdFeB magnets

采用粉末冶金法制备了质量配比为(Nd,Pr)29.9–x Cex(Fe,TM)69.12B0.98(x=0,1,2,4,6;TM=Co、Al、Nb、Cu、Ga)的烧结磁体,研究了Ce取代量对磁体微观结构、磁性能和抗弯强度的影响。结果表明:与w(Ce)=0的磁体相比,w(Ce)=1%的磁体微观结构明显改善,磁体具有更高的剩磁Br和相近的内禀矫顽力Hcj;随着w(Ce)继续增加,磁体的微观结构基本不变,但各项磁性能均不同程度地降低,这是磁体微观结构与其内禀磁特性综合作用的结果。Ce取代Nd提高了磁体的抗弯强度,当w(Ce)从0增加到2%时,磁体的抗弯强度逐渐增大;当w(Ce)≥4%时,抗弯强度略有减小。

The effects of Ce substitution amount on microstructure, magnetic properties and bending strength of sintered （Nd, Pr）29.9-xCex（Fe, TM）69.12B0.98 （x=0, 1, 2, 4, 6, mass proportion; TM=Co, Al, Nb, Cu, Ga） magnets prepared by the powder metallurgy process were investigated. The results show that magnet with w（Ce）=1% possesses higher remanence, nearly equal intrinsic coercive force and improved microstructure in comparison with magnet without Ce; with the increase of Ce substitution amount, the microstructure of magnets remains almost unchanged, but the magnetic properties all decrease at varying degrees, which is the combined effect of improved microstructure and reduced intrinsic magnetic properties. The substitution of Ce for Nd can improve the bending strength of magnets. The bending strength of magnets increases gradually, when w（Ce） increases from 0 to 2%; while the bending strength decreases insignificantly when w（Ce）≥4%.