The effects of carbon substitution on the behavior of hydrogen in Nd-Fe-B-type magnetic alloys

In the present study, the hydrogen absorption and desorption behavior of Nd -Fe-B-type alloys with the substitution of carbon for boron was investigate d focusing on the disproportionation and recombination reaction of the hydr ogenation, disproportionation, desorption and recombination (HDDR) process. Furthermore, the HDDR treatment of carbon-substituted Nd-Fe-B alloy was ca rried out. It was found that the most distinct effect of carbon substitutio n for boron in Nd-Fe-B-type alloy is the lowering of the starting temperatu re of disproportionation reaction in the HDDR process. The HDDR-treated Nd1 2.6Febal.Co11.6Ga1.0Zr0.1B4.0C2.0 powder shows better magnetic properties t han the Nd12.6Febal.Co11.6Ga1.0Zr0.1Br6.0 powder at short disproportionatio n reaction time. This may be due to the rapid disproportionation of Nd2Fe14 (B,C) phase at the disproportionation reaction temperature. (C) 2001 Elsevi er Science B.V. All rights reserved.