晶粒尺寸对NdFeB晶界扩散效果的影响  

Effect of Grain Size on Magnetic Properties in Grain Boundary Diffusion NdFeB Magnet

作　　者：程星华[1] 李建[1] 刘涛[1] 周磊[1] 喻晓军[1] 李波 Cheng Xinghua;Li Jian;Liu Tao;Zhou Lei;Yu Xiaojun;Li Bo(Advanced Technology&Materials Co.,Ltd.,Beijing 101318,China;China Iron&Steel Research Institute Group,Beijing 100081,China)

机构地区：[1]安泰科技股份有限公司,北京100081 [2]中国钢研科技集团有限公司,北京100081

出　　处：《中国稀土学报》2020年第6期752-758,共7页Journal of the Chinese Society of Rare Earths

基　　金：安泰科技股份有限公司技术创新项目(2017ZL01TGN)资助。

摘　　要：通过气流磨工艺将相同配比成分的NdFeB合金片粉碎成不同粒度的粉末,并经压制成型和烧结工艺制备出不同晶粒尺寸的基础烧结NdFeB永磁体,在相同工艺的镝晶界扩散工艺处理后形成晶界扩散磁体。通过实验研究分析,对比Dy晶界扩散前后磁体的晶粒尺寸变化、磁性能变化、Dy含量和微观结果的变化,结果表明:晶粒尺寸在扩散过程中有轻微长大现象,晶粒尺寸4.46μm的基础磁体样品在Dy晶界扩散后,晶粒尺寸长大到5.21μm,样品矫顽力Hcj提高了571 kA·m^-1,晶粒尺寸越小的基础磁体其面内晶界密度越大,相同工艺扩散过程中的Dy扩散量越多,面内晶界密度越大,扩散后的矫顽力提升量更多。The Nd-Fe-B alloy flakes with the same composition were crushed into powders with different sizes by jet milling process,and the base sintered Nd-Fe-B permanent magnets with different grain sizes were prepared through subsequent pressing and sintering process.Thereafter,the magnets were treated under a uniform Dy grain boundary diffusion process(GBDP).The changes of grain size,magnetic properties,dysprosium content and microstructure of the GBDP magnets were analyzed then.The results showed that the grain size of magnet has slightly grown during GBD process.The grain size of base magnet with 4.46μm grew to 5.21μm,the coercivity of the specimen increased by 571 kA·m^-1.The smaller grain size is,the higher grain-boundary distribution density will be.As a result,a more Dy diffusion content and a higher coercivity is achieved in the finer grain magnet.

关 键 词：钕铁硼 晶界扩散 晶粒尺寸 磁性能 矫顽力 

分 类 号：TM273[一般工业技术—材料科学与工程]