多元素协同晶界扩散:现状与发展  

Multi-element synergetic grain boundary diffusion:current status and development

作　　者：贾镐阳 洪源 赵利忠 张雪峰 JIA Haoyang;HONG Yuan;ZHAO Lizhong;ZHANG Xuefeng(School of Materials and Environmental Engineering,Hangzhou Dianzi University,Hangzhou 310018,Zhejiang,China)

机构地区：[1]杭州电子科技大学材料与环境工程学院,浙江杭州310018

出　　处：《金属功能材料》2024年第6期157-171,共15页Metallic Functional Materials

基　　金：国家自然科学基金杰出青年基金(52225312);国家自然科学基金优秀青年基金(52422106);国家自然科学基金面上项目(52171175)。

摘　　要：航空航天、新能源、轨道交通等领域的发展对高性能高温度稳定性钕铁硼永磁提出了紧迫的需求。高性能磁体对战略重稀土Dy、Tb的依赖导致了中国稀土资源应用不平衡的现状,而晶界扩散技术可通过在晶粒表面形成重稀土壳层大幅提升矫顽力,是目前重稀土利用最高效的技术,近年来在国内外引起了广泛关注和大范围产业化推广。然而,目前产业普遍采用纯重稀土及其化合物作为扩散源,存在重稀土容易在表层堆积、扩散深度浅和利用效率低等问题。基于国内外最新进展和作者团队的研究工作,本文讨论了不同元素在钕铁硼中的冶金行为和扩散特性,提出利用轻稀土和非稀土元素部分替代重稀土形成合金扩散源的思路,通过多元素协同作用实现重稀土壳层局域化,大幅提升重稀土扩散效率,降低扩散成本。同时对不同元素在扩散过程中对磁体矫顽力、温度稳定性、力学性能和耐蚀性等方面的作用进行了阐述,并对未来发展方向进行了展望。Development of aerospace,renewable energy,rail transportation,and other fields has created an urgent demand for high-performance Nd-Fe-B permanent magnets with superior temperature stability.The reliance of highperformance magnets on strategic heavy rare earths(Dy and Tb)has led to an imbalance in the application of rare earth resources in China.Grain boundary diffusion(GBD)technology,which significantly enhances coercivity by forming heavy rare earth shells on grain surfaces,is currently the most efficient technique for utilizing heavy rare earths.In recent years,it has attracted widespread attention and extensive industrial adoption worldwide.However,the industry predominantly employs pure heavy rare earths as diffusion sources,resulting in challenges such as heavy rare earth accumulation on the surface,shallow diffusion depths,and low utilization efficiency.Based on the latest international progress and the research of our group,this paper discusses the metallurgical behavior and diffusion characteristics of different elements in Nd-Fe-B magnets.It proposes a novel approach of partially substituting heavy rare earths with light rare earths and non-rare earth elements to create alloy-based diffusion sources.Through the synergistic effects of multiple elements,localized heavy rare earth shell formation can be achieved,significantly improving diffusion efficiency and reducing costs.The effects of different elements on the coercivity,temperature stability,mechanical properties,and corrosion resistance of magnets during the diffusion process are also elaborated.Finally,the future development directions in this field are outlined.

关 键 词：晶界扩散 稀土元素 扩散行为 多元素协同 

分 类 号：F42[经济管理—产业经济]