Anisotropic Nd–Fe–B nanocrystalline magnets processed by spark plasma sintering and in situ hot pressing of hydrogenation–decomposition–desorption–recombination powder

An anisotropic full density Nd–Fe–B nanocrystalline magnet was produced by spark plasma sintering of hydrogenation–decomposition–desorption–recombination processed powder and subsequent in situ hot deformation. The in situ hot deformation caused the Nd2Fe14B grains elongated normal to the applied pressure with an enhanced c-axis texture. Accordingly, the remanence (Br) and maximum energy product were improved from 1.07 to 1.35 T and 192 to 224 kJ m−3, respectively, with a slightly reduced coercivity (Hc) of ∼1000 kA m−1.