Simultaneously enhancing coercivity and remanence of hot-deformed Nd-Fe-B magnets by fl ake copper powder assisted DyF 3 inter fl ake addition

It is still a challenge to simultaneously enhance coercivity ( H cj ) and remanence ( J r ) of hot -deformed NdFe-B magnet due to the coercivity-remanence trade-off dilemma. Here, we achieved this balance between H cj and J r by flake Cu powder assisted DyF 3 interflake addition. The H cj increases from 1218 to 1496 kA/m and J r increases from 1.32 to 1.34 T compared with the original magnet. Results show that the width of coarse grain layers reduces because of the introduction of flake Cu, which increases the contact areas of the adjacent grains at ribbon interfaces and suppresses the excessive growth of grains. The stronger degree of texture and higher density compared with the original magnet should take the responsibility for the increase of J r . Additionally, the aggregation regions of rare earth rich (RE -rich) phase reduce and the betterment of the microstructure is another reason for the enhancement of J r in the flake Cu aided DyF 3 hot -deformed magnet. This strategy of using flake powder additives provides a promising method for optimizing microstructure and enhancing magnetic properties of hot -deformed Nd-Fe-B magnets. (c) 2024 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.