烧结钕铁硼磁体DyF_3晶界扩散工艺研究  

Grain Boundary Diffusion Process with DyF_3 Powders to Sintered Nd-Fe-B Magnets

作　　者：刘湘涟[1] 石建博[1] 应瑶[1] 周宁宁[1] LIU Xianglian SHI Jianbo YING Yao ZHOU Ningning(Ningbo University of Technology, Ningbo, Zhejiang, 315211, China)

机构地区：[1]宁波工程学院,浙江宁波315211

出　　处：《宁波工程学院学报》2017年第1期1-6,共6页Journal of Ningbo University of Technology

基　　金：国家自然科学基金(51671109)

摘　　要：应用DyF_3粉末作为镝源,对工业生产40H烧结钕铁硼磁体进行晶界扩散处理试验。结果表明,晶界扩散处理之后,磁体内禀矫顽力大幅度上升,同时其剩磁出现一定程度的下降;应用比较高的晶界扩散处理温度、比较长的晶界扩散处理时间有利于提高晶界扩散处理磁体的内禀矫顽力;在一定的晶界扩散处理温度和时间条件下,随着磁体厚度尺寸减小,晶界扩散处理磁体的内禀矫顽力明显提高。在1218K保持2h是较为理想的晶界扩散处理工艺制度。经过在1218K保持2h的晶界扩散处理,20mm×15mm×3.0mm尺寸规格的40H磁体的镝元素质量分数0.31%左右,而其内禀矫顽力上升幅度达到406.7k Am^(-1),剩磁下降0.0187T。Dy元素扩散进入富稀土晶界相中、并存在于主相晶粒表面区域,应为晶界扩散处理磁体矫顽力显著提高的基本原因。Grain boundary diffusion process experiments with DyF3 powders were conducted on mass-produced 40H sintered Nd-Fe-B magnets. According to the experimental results, intrinsic coercivity of magnets went up remarkably and their remanence went down to a certain degree after the grain boundary diffusion process; a higher diffusion temperature and a longer diffusion time led to a larger rise in the intrinsic coercivity of the magnets as processed by the grain boundary diffusion; and for given diffusion conditions, the processed magnets with a smaller thickness exhibited a larger rise in the intrinsic coersivity. A heat treatment at 1218 K for 2 h was a relatively ideal grain boundary diffusion process system. After the grain boundary diffusion process at 1218 K for 2 h, the 20mm×15mm×3.0mm 40H magnet had a Dy content of 0.31 wt %, and showed an increase of 406.7 kAm-1 intrinsic coercivity and a decrease of 0.0187 T remanence. Dy diffused into the Nd-rich phase and also existed in the surfacial region of matrix phase grains, which was believed to be the basic reason for the substantial rise in the intrinsic coercivity of the processed magnets.

关 键 词：烧结钕铁硼磁体 晶界扩散工艺 镝 微观结构 磁性能 

分 类 号：TM273[一般工业技术—材料科学与工程]