Preparation Technology, Application and Industrialization of HDDR Anisotropic NdFeB Magnetic Powders

HDDR technology is the best way to prepare anisotropic Nd-Fe-B magnetic powders. HDDR anisotropic Nd-Fe-B magnetic powder gradually expands its market share in high-end application scenarios of bonded permanent magnet materials by virtue of its excellent magnetic properties and cost performance. In addition，HDDR technology has potential important application value in the preparation of low weight rare earth high coercivity sintered Nd-Fe-B magnets，hot pressed Nd-Fe-B magnets，Sm-Fe-N magnetic powders and recycling of sintered Nd-Fe-B waste magnets. Therefore，HDDR anisotropic NdFeB magnetic powders and related technologies have attracted wide attention，and have become one of the research hotspots in the rare earth permanent magnet industry. HDDR anisotropic NdFeB magnetic powders have been successful in mass production and large-scale application in Japan，but its industrialization has not been successful in China so far. In this paper，the technological process，anisotropy formation mechanism，main application fields and industrialization status of the preparation of anisotropic NdFeB magnetic powders by HDDR method in the past 20 years are summarized，and its future development trend is prospected. © 2024 Editorial Office of Chinese Rare Earths. All rights reserved.