Abstract: A R—Fe—B base permanent magnet material is composed of a R—Fe—B magnet alloy which contains 87.5-97.5 vol % of a Fe14R2B1 primary phase and 0.1-3 vol % of a rare earth oxide or a rare earth and transition metal oxide. The alloy contains as a major component in its metal structure a compound selected from among zirconium-boron compounds, niobium-boron compounds and hafnium-boron compounds. The compound has an average grain size of at most 5 &mgr;m and is uniformly distributed within the alloy such that the maximum interval between neighboring grains of the compound is at most 50 &mgr;m. Rare-earth permanent magnet materials of this composition and structure have excellent magnetic properties.

Abstract: A R—Fe—B base permanent magnet material is composed of a R—Fe—B magnet alloy which contains 87.5-97.5 vol % of a Fe14R2B1 primary phase and 0.1-3 vol % of a rare earth oxide or a rare earth and transition metal oxide. The alloy contains as a major component in its metal structure a compound selected from among zirconium-boron compounds, niobium-boron compounds and hafnium-boron compounds. The compound has an average grain size of at most 5 &mgr;m and is uniformly distributed within the alloy such that the maximum interval between neighboring grains of the compound is at most 50 &mgr;m. Rare-earth permanent magnet materials of this composition and structure have excellent magnetic properties.

Abstract: Disclosed is a rare earth/iron/boron-based permanent magnet alloy composition capable of giving, by a powder metallurgical process, a permanent magnet having excellent coercive force and residual magnetization as well as good squareness ratio of the hysteresis loop. The magnet alloy composition consists of: (a) from 28 to 35% by weight of a rare earth element selected from the group consisting of neodymium, praseodymium, dysprosium, terbium and holmium; (b) from 0.1 to 3.6% by weight of cobalt; (c) from 0.9 to 1.3% by weight of boron; (d) from 0.05 to 1.0% by weight of aluminum; (e) from 0.02 to 0.25% by weight of copper; (f) from 0.02 to 0.3% by weight of zirconium or chromium; (g) from 0.03 to 0.1% by weight of carbon; (h) from 0.1 to 0.8% by weight of oxygen; (i) from 0.002 to 0.2% by weight of nitrogen; and (j) the balance to 100% by weight of iron and unavoidable impurity elements.