| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1799803 | Journal of Magnetism and Magnetic Materials | 2014 | 5 Pages |
•Low melting-point Dy32.5Fe62Cu5.5 alloy was introduced to NdFeB magnets.•The doped magnet exhibits enhanced coercivity and maximum energy product.•(Nd,Dy)2Fe14B shell was expected to form in the surface of Nd2Fe14B grains.•The continuous grain boundary layer formed between neighboring Nd2Fe14B grains.
To improve coercivity without sacrificing other magnetic performance of NdFeB sintered magnets, a low melting point Dy32.5Fe62Cu5.5 alloy was introduced as an intergranular additive. Magnetic properties and microstructure of the magnets with different Dy32.5Fe62Cu5.5 contents were studied. At the optimum addition of 3 wt%, coercivity Hcj was enhanced from 12.7 to 15.2 kOe, the maximum magnetic energy product (BH)max was simultaneously increased from 46.6 to 47.8 MG Oe, accompanied by a slight reduction in remanence Br. Further investigation on microstructure and grain boundary composition indicated that the enhanced Hcj and (BH)max could be attributed to the refined and uniform 2:14:1 phase grains, continuous grain boundaries and a (Nd,Dy)2Fe14B hardening shell surrounding the 2:14:1 phase grains.
