| Title |
Pulverization and Degradation Phenomena in Nd - Fe - B Permanent Magnetic alloys upon the Hydrogen Absorption - Desorption Cycling |
| Authors |
박충년(Choong Nyeon Park); 최유(Jeon Choi); 이병택(Byung Teak Lee); 정원용(Won Yong Jeung) |
| Abstract |
The pulverization and alloy degradation phenomena in Nd_(15)Fe_(77)B_8 and Nd_(12)Fe_(70)Co_(10)B_7Ga₁ alloys upon the hydrogen absorption and desorption cycling have been investigated by measuring hydrogen solubility changes, microstructure observation and DSC thermal analysis. The cycling was performed by varing the temperature from 25℃ to 400℃ at a constant hydrogen pressure. As the number of cycles increased upto 15 cycles, the hydrogen solubility decreased markedly implying severe alloy degradations in both alloys, whereas the pulverization progressed small. The degadation could be attributed to the segregation of Nd or the precipitation of Nd-rich phases on the alloy surface and to the oxidation of those phases. |