Praseodymium-rich iron-boron-rare earth composition, permanent magnet produced therefrom, and method of making

摘要

A permanent magnet having substantially stable magnetic properties is disclosed having as the active magnetic component a sintered product of compacted particulate iron-boron-rare earth intermetallic material, said sintered product having pores which are substantially non-interconnecting, a density of at least 87 percent of theoretical and a composition consisting essentially of in atomic percent about 13 to about 19 percent rare earth elements, about 4 to about 20 percent boron and about 61 to about 83 percent of iron with or without impurities; where the rare earth content is greater than 50 percent praseodymium with an effective amount of a light rare earth selected from the group consisting of cerium, lanthanum, yttrium and mixtures thereof, and balance neodymium.