Title :
Effect of temperature and pressure conditions on phase evolution and magnetic anisotropy in d-HDDR process for Nd-Fe-B powders
Author :
Horikawa, T. ; Matsuura, M. ; Sugimoto, S. ; Yamazaki, M. ; Mishima, C.
Author_Institution :
Dept. of Mater. Sci., Tohoku Univ., Sendai, Japan
Abstract :
It is well-known that by applying the HDDR (hydrogen disproportionation desorption recombination) treatment to Nd-Fe-B powders, the resultant powders show magnetic anisotropy and such an anisotropic powders are useful to fabricate high performance bonded magnets. The degree of magnetic anisotropy of HDDR-treated Nd-Fe-B powders varies depending on the temperature and hydrogen pressure (PH2) during the treatment and also in d(dynamic)-HDDR method there is an optimal condition which maximizes the anisotropy.[1,2] Many researchers have been tried to reveal the origin of this anisotropy, however, it is still unclear. In the present study, to clarify the mechanism of the induction of magnetic anisotropy, the relationship between the d-HDDR condition and the properties of obtained samples was investigated from the aspect of both the evolution in phases and the crystal structure.
Keywords :
crystal structure; iron compounds; magnetic anisotropy; neodymium compounds; permanent magnets; powders; NdFeB; crystal structure; d-HDDR process; high performance bonded magnets; hydrogen disproportionation desorption recombination treatment; hydrogen pressure; magnetic anisotropy; phase evolution; powders; pressure condition; temperature condition; High definition video; Hydrogen; Iron; Lattices; Magnetic anisotropy; Powders; X-ray scattering;
Conference_Titel :
Magnetics Conference (INTERMAG), 2015 IEEE
Conference_Location :
Beijing
Print_ISBN :
978-1-4799-7321-7
DOI :
10.1109/INTMAG.2015.7156667
