Properties of rapidly solidified Nd-Fe-Ga-Co-B alloys

Investigations carried out to study the properties of rapidly solidified Nd-Fe-B alloys containing gallium and cobalt are reported. The gallium content that gives maximum room-temperature B/sub r/ and BH/sub max/ was found to be 0.6 wt.%. Further investigations were carried out with 0.6 wt.% gallium and varying cobalt contents. Transmission electron micrographs of the ribbons indicate a three-phase structure as compared to the two-phase structure in Nd-Fe-B alloys. The three phases are Nd/sub 2/(Fe,Co)/sub 14/B, Nd(Fe,Co)/sub 4/B, and a neodymium-iron-gallium grain boundary phase. The latter phase is depleted in iron, which is believed to increase the coercive force by increasing its effectiveness as a pinning site. Anisotropic magnets were prepared from the above alloys by hot deformation techniques. Energy products up to 40 MGOe were achieved with a magnet uniformity of +or-1.5 MGOe through the cross section.<
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