Magnetic properties, microstructure and corrosion behavior of (Pr,nd)12.6Fe81.3B6.1-type sintered magnets doped with (Pr,nd)30Fe62Ga8

Abstract NdFeB sintered magnets with (Pr,Nd) 30 Fe 62 Ga 8 were prepared by a binary powder blending method and their magnetic properties, microstructure and corrosion behavior were investigated. Addition of 3 wt% (Pr,Nd) 30 Fe 62 Ga 8 was found to be the most effective for improving (BH) max and i H c of the magnets. The increase in both magnetic parameters was related to the alteration in microstructure. However, in other samples the occurrence of micropore and the aggregation of intergranular phases harmed the magnetic properties. Such disadvantageous microstructure features also caused higher corrosion current density, thus decreasing the corrosion resistance of the sample with higher additive content. In addition, the Ga-containing intergranular phases that are more stable than the (Pr,Nd)-rich phase formed in the additive doped magnets, leading to better corrosion resistance of the 3 wt% additives doped sample in comparison with the contrastive sample.