Место издания:The University of Salford Manchester, UK
Первая страница:405
Последняя страница:405
Аннотация:In spite of the fact that a lot of works are devoted to hydrogen interaction with
Sm2Fe17 and R2Fe14B intermetallic compounds and alloys of Nd-Fe-B system, a number
of aspects, such as influence of hydrogenation and absorbtion-desorption cycling on
magnetocrystal anisotropy and mechanism of its formation, are studied insufficiently.The
relationship between the quantity of absorbed hydrogen and the dimensions and
morphology of hydride particles is not find out, though this data is necessary for correct
design of reactors for hydriding of magnetic alloys.
In present work the influence of hydriding-dehydriding procedures on the phase
composition, structure and powder morphology of mechanoactivated R2Fe14B-based
alloys. It was found that the high-energy milling leads to increase of coercitivity of
dehydrided powders up to 2.4 kOe, that is almost 10 times higher than coercitivity of the
as-cast alloy. Also, mechanoactivation of as-cast R2Fe14B alloy results in formation of
two types of amorphous regions with different composition.
In case of Sm-Fe-N alloys the phase composition, structure and magnetic properties of
Sm2Fe17Nх nitrides, obtained by nitrigenation of Sm2Fe17 both as milled powder and HD
powder, are almost the same. However, HD process significantly accelerates the nitride
formation. Additional mechanoactivation of hydrides leads to increase of coercitivity of
nitrides.
The analysis of the changes of the remagnetisation and partial hysterisis loop curves,
depending on the obtaining conditions and the duration of milling, shows that the limiting
stage of the remagnetisation processes in nitirides is the generation and groth of reverse
magnetisation domains.