Title :
Effect of small dysprosium additions on the coercivity of melt-spun Nd-Fe-C alloys
Author :
Jang, Taesuk ; Kim, Y.S.
Author_Institution :
Dept. of Metall. & Mater., Sun Moon Univ., Choongnam, South Korea
fDate :
9/1/1999 12:00:00 AM
Abstract :
The influence of small dysprosium additions on the microstructural development and the coercivity of melt-spun iron-rich Nd15-xDyxFe77C8 (x=0.5-5.0) alloys was investigated. By X-ray diffraction analysis, it was, found that amorphization of as-spun ribbons spun at 25 m/s was promoted by increasing the Dy addition. The ribbons became fully amorphous with 5.0 at.% Dy. Small additions of Dy not only improved the thermal stability of Nd2Fe14C, which was obtained by a proper annealing, but also enhanced the grain refinement of the Nd2Fe14C, resulting in a large increase in coercivity. When the addition of Dy was more than 3.0 at.%, the intrinsic coercivities of more than 17 kOe, which would be the highest coercivity ever obtained from iron-rich Nd-Fe-C alloys, were easily obtained after annealing 10 min. at 800-900°C
Keywords :
X-ray diffraction; alloying additions; amorphisation; amorphous magnetic materials; annealing; coercive force; dysprosium alloys; ferromagnetic materials; grain refinement; iron alloys; melt spinning; neodymium alloys; permanent magnets; thermal stability; (NdDy)15Fe77C8; 10 min; 800 to 900 C; Dy addition; X-ray diffraction; amorphization; annealing; as-spun ribbons; coercivity; grain refinement; intrinsic coercivities; melt-spun Nd-Fe-C alloys; melt-spun iron-rich Nd15-xDyxFe77C8; microstructural development; small dysprosium additions; thermal stability; Amorphous materials; Annealing; Coercive force; Copper alloys; Iron alloys; Orifices; Spinning; Surface cracks; Wheels; X-ray diffraction;
Journal_Title :
Magnetics, IEEE Transactions on
