回收制备烧结Nd-Fe-B磁体的磁性能与耐热性能

Magnetic Properties and Thermal Stability of Nd-Fe-B Magnets by Recycling Fabrication

以废旧钕铁硼磁体为原料,采用短流程回收制备技术制备了烧结Nd-Fe-B磁体,通过添加镨钕混合稀土研究了磁体的磁性能和耐热性能。结果表明,在回收磁体中添加2%PrNd,制备的烧结Nd-Fe-B磁体的剩磁为1.31T、矫顽力为1 474.86kA/m、磁能积为353.90kJ/m^3。与一次成品相比矫顽力恢复到102%,剩磁恢复到95%,磁能积恢复到90%。在293~393K范围内未掺杂PrNd磁体的矫顽力温度系数为-0.589 9%/K,掺杂2%PrNd磁体的矫顽力温度系数为-0.556 4%/K,提高了磁体在高温下的耐热性能。这是由于添加混合稀土PrNd增强了主相晶粒间的去磁交换耦合作用,提高了主相的磁晶各向异性场,从而提高了磁体的矫顽力和耐热性能。

The sintered Nd-Fe-B magnets were fabricated by short-circuit recycling process.The magnetic properties and thermal stability of the magnets with adding PrNd mixed rare earth were also investigated.The magnetic properties of the magnets with 2%PrNd addition were as follows:the remanence(B r)of 1.31 T,the coercivity(H cj)of 1 474.86 kA/m,and the maximum energy product[(BH)max]of 353.90 kJ/m 3.Compared to the new qualified magnets,the B r,H cj and(BH)max values of 95%,102%and 90%,respectively,were recovered.The magnet thermal stability could be improved by PrNd addition.The temperature coefficient of the coercivity reduced from-0.589 9%/K to-0.556 4%/K in the range of 293-393 K.This is mainly because the addition of mixed rare earth PrNd enhances the demagnetization exchange coupling and the magnetocrystalline anisotropy field of the main phase.Thus the coercivity and thermal stability of the magnets are improved.