The effects of additive elements and hydrogen pressure on the behaviour of hydrogen in Nd-Fe-B type alloys

Abstract

In this study, the hydrogen absorption and desorption behaviour of Nd-Fe-B type alloys with the addition of Co and Ga, and hydrogen pressure was investigated. The starting temperature of hydrogen absorption into Nd-rich and Nd2Fe14B phase is shifted to higher temperature by the addition of Co and Ga. The most distinct effect of Co and Ga addition on hydrogen absorption and desorption behaviour in Nd-Fe-B type alloy is the lowering of occurring temperature of recombination reaction. The initial hydrogen pressure also affect the hydrogen absorption and desorption behaviour. The disproportionation reaction occurred sluggish at low hydrogen pressure and the occurring temperature of recombination reaction is lowered by decreasing the initial hydrogen pressure.