新型富La/Ce多主相稀土永磁材料研究  

Research on the La/Ce-rich multi-main-phase RE-Fe-B permanent magnetic materials

作　　者：严密[1] 金佳莹 马天宇 王新华[1] 

机构地区：[1]浙江大学材料科学与工程学院

出　　处：《金属功能材料》2018年第1期1-9,共9页Metallic Functional Materials

基　　金：国家自然科学基金项目资助(51590881,51571176,51622104);国家重点研发计划项目资助(2016YFB0700902)

摘　　要：钕铁硼是目前磁性最强、应用最广、消耗稀土最多的永磁材料。钕铁硼的多年快速增长,导致我国稀土资源利用极不平衡,其高度依赖的Nd、Pr、Dy、Tb等昂贵稀土资源日益紧缺,而La、Ce等廉价的高丰度稀土则大量积压。扩大高丰度的La、Ce在钕铁硼中的应用,发展低成本高性能磁体,已成为稀土永磁材料的重要研究方向。然而,La/Ce均匀取代Pr/Nd,会降低RE2Fe14B四方相的內禀磁性能,导致强烈的磁稀释效应。通过设计富Nd和富La-Ce两类主相合金,制备多主相RE-Fe-B磁体,即La/Ce在主相晶粒内部和晶粒间的分布是不均匀的。这种化学不均匀性导致单个晶粒内部强烈的短程交换作用,以及晶粒间的长程静磁耦合,保障了富La/Ce磁体的磁性能。同时富La/Ce多主相磁体的抗腐蚀性能和力学性能也满足了商业化应用的要求。Nd2Fe14 B-type sintered magnets with outstanding magnetic performance have served as indispensable components for both the industrial and household products. The continually growing demand for Nd-Fe-B magnets has led to the overuse of critical rare earth （RE） elements including Nd/Pr/Dy/Tb, whereas the abundant and cheap La/Ce are overstocked. Incorporation of La/Ce into the 2 ： 14 ： 1-type permanent magnets is beneficial to balance the utilization of RE sources and lower the material cost. On account of inferior intrinsic properties of La2Fe14 B and Ce2 Fel~ B to Nd2 Fell B compound, directly alloying La/Ce into the 2 ：14 ： 1 lattice severely deteriorates the magnetic properties. Here we report high figure of merit La/Ce-rich RE-Fe-B permanent magnets based on the new prototype of multi main phase （MMP） approach （mixing the La/Cc free and La/Ce-rich RE2Fe14 Btype components）. The RE concentration in the main phase differs a lot either over local regions within an individual grain or across grains. The resultant short-range exchange couplings of local regions within an individual 2 ： 14 ： 1 main phase grain, and the long-range magnetostatic interactions among different 2 ： 14 ： 1-type grains facilitate superior magnetic performance of MMP magnets. Meanwhile, the La/Ce-rich MMP magnets also exhibit preferable corrosion resistance and me chanical properties, which are also critical criteria when assessing their applicability.

关 键 词：富La/Ce 多主相 RE-Fe-B 磁性能 抗蚀性 力学性能 

分 类 号：TM273[一般工业技术—材料科学与工程]