Loading...
Please wait, while we are loading the content...
Similar Documents
Improvement in coercivity, thermal stability, and corrosion resistance of sintered Nd–Fe–B magnets with Dy$ _{80}$ Ga$ _{20}$ intergranular addition
| Content Provider | Scilit |
|---|---|
| Author | Zhou, Beibei Li, Xiangbin Cao, Xuejing Yan, Gaolin Yan, Aru |
| Copyright Year | 2016 |
| Description | Journal: Chinese Physics B To investigate the coercivity, corrosion resistance, and thermal stability of Nd–Fe–B magnets, their properties were investigated at room and high temperature before and after doping with $Dy_{80}Ga_{20}$ (at.%) powder. The coercivity of the magnets increased from the undoped value of 12.72 kOe to a doped value of 21.44 kOe. A micro-structural analysis indicates that a well-developed core-shell structure forms in the magnets doped with $Dy_{80}Ga_{20}$ powder. The improvement in magnetic properties is believed to be related to the refined and uniform matrix grains, continuous grain boundaries, and a hardened (Nd, $Dy)_{2}Fe_{14}$B shell surrounding the matrix grains. Additionally, the doped magnets exhibit an obvious improvement in thermal stability. For the magnets with added $Dy_{80}Ga_{20}$ powder, the temperature coefficients of remanence (α) and coercivity (β) increased to −0.106% $°C^{−1}$ and −0.60% $°C^{−1}$ over the range 20–100 °C, compared to temperature coefficients of −0.117% $°C^{−1}$ (α) and −0.74% $°C^{−1}$ (β) in the regular magnets without $Dy_{80}Ga_{20}$ powder. The irreversible loss of magnetic flux (Hirr) was investigated at different temperatures. After being exposed to 150 °C for 2 h, the Hirr of magnets with 4 wt.% $Dy_{80}Ga_{20}$ decreased by ~95% compared to that of the undoped magnets. The enhanced temperature coefficients and Hirr indicate improved thermal stability in the doped Nd–Fe–B magnets. The intergranular addition of $Dy_{80}Ga_{20}$ also improved the corrosion resistance of the magnets because of the enhanced intergranular phase. In a corrosive atmosphere for 96 h, the mass loss of the sintered magnets with 4 wt.% $Dy_{80}Ga_{20}$ was 2.68 $mg/cm^{2}$, less than 10% of that suffered by the undoped magnets (28.1 $mg/cm^{2}$). |
| Related Links | http://iopscience.iop.org/article/10.1088/1674-1056/25/11/117504/pdf |
| ISSN | 16741056 |
| e-ISSN | 20583834 |
| DOI | 10.1088/1674-1056/25/11/117504 |
| Journal | Chinese Physics B |
| Issue Number | 11 |
| Volume Number | 25 |
| Language | English |
| Publisher | IOP Publishing |
| Publisher Date | 2016-11-01 |
| Access Restriction | Open |
| Subject Keyword | Journal: Chinese Physics B Condensed Matter Physics Thermal Stability Intergranular Addition |
| Content Type | Text |
| Resource Type | Article |
| Subject | Physics and Astronomy |
