重稀土掺杂烧结钕铁硼磁体的晶界调控研究进展

Research Progress on Grain Boundary Regulation of Sintered NdFeB Magnets Doped by Heavy Rare Earth

随着低碳经济的提出,烧结钕铁硼磁体作为新能源汽车及其他高新技术的核心材料越来越受到人们的关注,同时对其性能也提出了更高的要求,高矫顽力、高剩磁和大磁能积的永磁体成为人们追求的目标。烧结钕铁硼磁体的磁性能与微观结构中晶界成分、分布以及体积分数等密切相关。利用新型工艺在合金中掺杂重稀土可以很好地调控磁体的微观结构,从而在保持剩磁不变的基础上,提高磁体的矫顽力和磁能积。本文在详细介绍两种新型掺杂技术的基础上,梳理了近几十年来国内外通过掺杂重稀土金属、重稀土化合物及重稀土合金来调控磁体晶界结构、提高磁体矫顽力方面的最新研究成果,为进一步提高烧结钕铁硼磁体性能提供参考。

With the proposal of low carbon economy, sintered NdFeB magnets have attracted more and more attention as the core material of new energy vehicles and other high-tech. At the same time, people also put forward higher requirements for the performance of sintered NdFeB magnets, and permanent magnets with high coercivity, high remanence and large magnetic energy product have become the goal pursued by people. The magnetic properties of sintered NdFeB magnets are closely related to the composition, distribution and volume fraction of grain boundaries in the alloy microstructure. Doping heavy rare earths in alloys by a new process can well regulate the microstructure of the magnets, thereby improving the coercive force and magnetic energy product of the magnets on the basis of keeping the remanence unchanged. Based on the detailed introduction of two new doping technologies, the latest research results in recent decades in regulating the grain boundary structure of magnets and improving the coercive force of magnets by doping heavy rare earth metals, heavy rare earth compounds and heavy rare earth alloys are reviewed. The research provides a reference for further improving the performance of sintered NdFeB magnets.