Effects of Dy on magnetic properties of alpha-Fe/Nd2Fe14B type alloy

The effects of Dy content magnetic and microstructural properties of melt-s pun (Nd1-xDyx)(4)(Fe0.9Co0.1)(86)B6Nb3Cu alloys have been investigated. The energy product of the alloys decreases with the increase of Dy content, wh ile the coercivity increases up to 2.64 kOe at x = 0.3. At a fixed annealin g time condition, the optimum annealing temperature increases by Dy substit ution, and grain coarsening occurs in the alloys with high Dy content. The deterioration of hard magnetic properties by Dy substitution is due to the decrease of exchange interaction between alpha-Fe and (Nd,Dy)(2)Fe14B phase s by grain coarsening.