Defect formation in Fe14Nd2B grains, as caused by a low-pressure pack-sublimation Zn-coating process, was investigated. The results indicated that, within the Zn-affected region, low-angle boundaries which were decorated with precipitates formed within the grains. The Zn, which was almost insoluble in Fe14Nd2B, initially diffused along the grain boundaries and was then thought to cause extrinsic dislocations, in the grain boundaries, to migrate into the grains; thus forming low-angle boundaries. The Zn diffused along these low-angle boundaries and, when its concentration became high enough, it formed precipitates.

Defect Formation in Nd2Fe14B Grains Caused by Zn Diffusion. I.R.Harris, M.Aindow, I.P.Jones: Philosophical Magazine Letters, 2001, 81[4], 233-41