Preparation of anisotropic bonded NdFeB/SmFeN hybrid magnets by mixing two different size powders

[Display omitted] •NdFeB/SmFeN magnet is prepared by mixing ultra-fine SmFeN powders and NdFeB powders.•Addition of ultra-fine SmFeN powders makes the improvement of density.•Density reaches the maximum at 25 wt% SmFeN content.•DOA is increased by applying magnetic field when mixing powders.•(BH)max, DOA and density are increased by 35.71%, 7.75% and 9.68%. Anisotropic bonded NdFeB/SmFeN hybrid magnet, with high density and magnetic properties, are prepared by mixing ultra-fine SmFeN powders and coarse NdFeB powders under a magnetic field that is characterizedby a surface magnetic induction density of ∼3000 Gs using digital tesla meter. Magnetic powders and bonded magnets are characterized and analysed by scanning electron microscopy. The maximum energy product ((BH)max), degree of alignment (DOA) and density of 25 wt% NdFeB/SmFeN magnet mixing powders with magnetic field (114 kJ/m3, 0.556, 6.12 g/cm3) are increased by 10.68%, 16.32%, −1.13% than these of mixing powders without magnetic field (103 kJ/m3, 0.478, 6.19 g/cm3) and 35.71%, 7.75%, 9.68% than these of NdFeB magnets (84 kJ/m3, 0.516, 5.58 g/cm3). Effects of SmFeN powders entering into gaps between NdFeB powders and substitution of SmFeN on NdFeB make the actual density reach the maximum at the ideal mass ratio of 25%. And the oriented SmFeN agglomerate, produced by mixing powders with magnetic field, results in the increase of DOA of NdFeB/SmFeN magnet.