|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials Science for High-Performance Permanent Magnets
||Electrical Resistivity Enhancement by Doping with Eutectic DyF3–LiF Salt Mixture in Nd-Fe-B Die-upset Magnet
||Hae-Woong Kwon, Kyung Min Kim, Dong Hwan Kim, Jung Gu Lee, Ji Hoon Yu
|On-Site Speaker (Planned)
As an excessively high operating temperature of Nd-Fe-B magnet for traction motor in HEV, EV is due largely to eddy current, enhancing electrical resistivity of the magnet would be useful for decreasing the operating temperature. Enhancement of electrical resistivity in the Nd<SUB>13.6</SUB>Fe<SUB>73.6</SUB>Co<SUB>6.6</SUB>Ga<SUB>0.6</SUB>B<SUB>5.6</SUB> die-upset magnet was attempted by doping with low-melting point eutectic DyF<SUB>3</SUB>–LiF salt mixture (eutectic temperature ≈ 700 °C). The salt mixture doping (> 4 wt%) led to a remarkable enhancement of electrical resistivity from ca. 190 μΩ.cm to over 400 μΩ.cm. During die-upset (735 °C) the added eutectic salt mixture became liquid. Remarkable enhancement of the electrical resistivity was attributed to homogeneous and continuous coverage of the inter-flake boundaries by the easily-melting dielectric eutectic salt mixture. Coercivity was also slightly enhanced from 13.5 kOe to 14.6 kOe. The enhancement of electrical resistivity and coercivity were achieved at the expense of remanence (from 13.0 kG to 10.9 kG).