Magnetic and anticorrosion properties of two-powder (Pr, Nd)12.6Fe81.3B6.1-type sintered magnets with additions of (Pr, Nd)32.5Fe62.0Cu5.5

Aiming to improve the corrosion resistance without sacrificing magnetic properties, two-powder magnets were fabricated by additions of (Pr, Nd)32.5Fe62.0Cu5.5 aid alloys to (Pr, Nd)12.6Fe81.3B6.1 master alloys. It was found that these two-powder magnets have similarly comprehensive magnetic properties and even the magnet with 12 wt% additives possesses better magnetic/anticorrosion properties than contrastive one-powder magnets of (Pr, Nd)14.5Fe79.5B6.0 and (Pr, Nd)14.5Fe79.5Cu0.5B5.5. Higher corrosion resistance of the two-powder magnets are related to the replacement of (Pr, Nd)-rich intergranular phase by (Pr, Nd)6Fe13Cu. It is due to the higher corrosion stability of (Pr, Nd)6Fe13Cu, which inhibits the formation of active reaction channels, thus decreasing the corrosion current density and improving the corrosion resistance.