Two-step diffusion method for preparing high-performance dual-main-phase sintered mischmetal-iron-boron magnet

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United States of America Patent

PATENT NO 11742120
SERIAL NO

17520452

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A two-step diffusion method for preparing high-performance dual-main-phase sintered mischmetal-iron-boron magnet belongs to the preparing technical field of rare earth permanent magnet materials. The compositions of the two main phase alloys are RE-Fe—B (RE is Nd or Pr) and (Nd, MM)-Fe—B (MM is mischmetal), respectively. First, PrHoFe strip-casting alloy is used as a diffusion source. Next, a PrHo-rich layer is uniformly coated on the surface of (Nd, MM)-Fe—B hydrogen decrepitation powders. The higher anisotropic fields of Pr2Fe14B and Ho2Fe14B are used to improve the coercivity. Then, the ZrCu strip-casting alloy is used as a diffusion source. A Zr-rich layer is uniformly coated on the surface of the powders after the first-step diffusion, which prevents the growth of the MM-rich main phase grains during the sintering process and the inter-diffusion between the two main phases, thus obtaining high coercivity.

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BEIJING UNIVERSITY OF TECHNOLOGY100022 NO 100 CHAOYANG DISTRICT PING TIAN PARK BEIJING BEIJING CITY BEIJING CITY 100022

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Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Chen, Hao Beijing, CN 1012 6150
Li, Yuqing Beijing, CN 31 181
Li, Zhi Beijing, CN 468 3824
Liu, Weiqiang Beijing, CN 23 185
Yin, Yantao Beijing, CN 1 1
Yue, Ming Beijing, CN 20 20
Zhang, Hongguo Beijing, CN 3 1

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