Effect of Processing on Permanent Magnet Materials Containing Rare-Earth Metals

It is established that the new rare-earth permanent magnet alloys containing copper show precipitation effects during heat treatment. Alloys drastically quenched from a high temperature had a comparatively low value of coercive force which increased substantially upon aging at a lower temperature. Also, upon aging, it was observed optically that a precipitate formed. These effects permit considerable latitude in the heat treatment of the alloys. Experiments on coarse powders showed that useful permanent magnet properties can be obtained with alloys in this form. Oriented coarse powder compacts which are stable in air having intrinsic coercive forces at 17 000 Oe have been made.