The HDDR(hydrogenation-disproportionation-desorption-recombination) process can be used as an effective way of converting no coercivity Nd-Fe-B material, with a coarse grain structure to a highly coercive one with a fine grain. Careful control of the HDDR process can lead to an anisotropic without any post aligning process. In this study, the effect of hydrogen gas input at various temperature in range of of hydrogenation stage (named Modified-solid HDDR, MS-HDDR) on the magnetic properties has been investigated. The powder from the modified-solid HDDR process exhibits Br of 11.7 kG and iHc of 10.7 kOe, which are superior to those of the powder prepared using the normal HDDR process.

• 이상협 | Lee S.H.
• 유지훈 | Yu J.H.
• 김양도 | Kim Y.D.