Abstract: A rare earth metal extractant in the form of a dialkyl diglycol amic acid is synthesized by reacting diglycolic anhydride with a dialkylamine in an aprotic polar solvent, with a molar ratio of dialkylamine to diglycolic anhydride being at least 1.0, and removing the aprotic polar solvent.

Abstract: A rare earth metal extractant in the form of a dialkyl diglycol amic acid is synthesized by reacting diglycolic anhydride with a dialkylamine in a synthesis medium. A molar ratio (B/A) of dialkylamine (B) to diglycolic anhydride (A) is at least 1.0. A non-polar or low-polar solvent in which the dialkyl diglycol amic acid is dissolvable is used as the synthesis medium.

Abstract: Solvent extraction from an aqueous phase containing first and second rare earth elements is carried out by contacting an organic phase containing a diglycolamic acid as an extractant and a hydrocarbon or a low-polar alcohol as a solvent, with the aqueous phase below pH 3 for extracting the first rare earth element into the organic phase, back-extracting from the organic phase with an aqueous acid solution for recovering the first rare earth element, and recovering the second rare earth element which has not been extracted into the organic phase and has remained in the aqueous phase.

Abstract: A rare-earth alloy ingot is produced by melting an alloy composed of 20-30 wt % of a rare-earth constituent which is Sm alone or at least 50 wt % Sm in combination with at least one other rare-earth element, 10-45 wt % of Fe, 1-10 wt % of Cu and 0.5-5 wt % of Zr, with the balance being Co, and quenching the molten alloy in a strip casting process. The strip-cast alloy ingot has a content of 1-200 ?m size equiaxed crystal grains of at least 20 vol % and a thickness of 0.05-3 mm. Rare-earth sintered magnets made from such alloys exhibit excellent magnetic properties and can be manufactured under a broad optimal temperature range during sintering and solution treatment.

Abstract: A rare-earth alloy ingot is produced by melting an alloy composed of 20-30 wt % of a rare-earth constituent which is Sm alone or at least 50 wt % Sm in combination with at least one other rare-earth element, 10-45 wt % of Fe, 1-10 wt % of Cu and 0.5-5 wt % of Zr, with the balance being Co, and quenching the molten alloy in a strip casting process. The strip-cast alloy ingot has a content of 1-200 ?m size equiaxed crystal grains of at least 20 vol % and a thickness of 0.05-3 mm. Rare-earth sintered magnets made from such alloys exhibit excellent magnetic properties and can be manufactured under a broad optimal temperature range during sintering and solution treatment.

Abstract: Hydrogen embrittlement is prevented in Sm2Co17-based magnets and R2Fe14B-based magnets by metal plating the magnet, then carrying out heat treatment, or by forming a metal oxide or metal nitride layer on the metal plating layer or directly on the magnet itself.

Abstract: A rare-earth alloy ingot is produced by melting an alloy composed of 20–30 wt % of a rare-earth constituent which is Sm alone or at least 50 wt % Sm in combination with at least one other rare-earth element, 10–45 wt % of Fe, 1–10 wt % of Cu and 0.5–5 wt % of Zr, with the balance being Co, and quenching the molten alloy in a strip casting process. The strip-cast alloy ingot has a content of 1–200 ?m size equiaxed crystal grains of at least 20 vol % and a thickness of 0.05–3 mm. Rare-earth sintered magnets made from such alloys exhibit excellent magnetic properties and can be manufactured under a broad optimal temperature range during sintering and solution treatment.

Abstract: A rare-earth alloy ingot is produced by melting an alloy composed of 20-30 wt % of a rare-earth constituent which is Sm alone or at least 50 wt % Sm in combination with at least one other rare-earth element, 10-45 wt % of Fe, 1-10 wt % of Cu and 0.5-5 wt % of Zr, with the balance being Co, and quenching the molten alloy in a strip casting process. The strip-cast alloy ingot has a content of 1-200 ?m size equiaxed crystal grains of at least 20 vol % and a thickness of 0.05-3 mm. Rare-earth sintered magnets made from such alloys exhibit excellent magnetic properties and can be manufactured under a broad optimal temperature range during sintering and solution treatment.

Abstract: A rare-earth alloy ingot is produced by melting an alloy composed of 20-30 wt % of a rare-earth constituent which is Sm alone or at least 50 wt % Sm in combination with at least one other rare-earth element, 10-45 wt % of Fe, 1-10 wt % of Cu and 0.5-5 wt % of Zr, with the balance being Co, and quenching the molten alloy in a strip casting process. The strip-cast alloy ingot has a content of 1-200 ?m size equiaxed crystal grains of at least 20 vol % and a thickness of 0.05-3 mm. Rare-earth sintered magnets made from such alloys exhibit excellent magnetic properties and can be manufactured under a broad optimal temperature range during sintering and solution treatment.

Abstract: Hydrogen embrittlement is prevented in Sm2Co17-based magnets and R2Fe14B-based magnets by metal plating the magnet, then carrying out heat treatment, or by forming a metal oxide or metal nitride layer on the metal plating layer or directly on the magnet itself.

Abstract: An alloy powder for bonded rare earth magnets is prepared by melting an alloy consisting essentially of 20-30 wt % of Sm or a mixture of rare earth elements (inclusive of Y) containing at least 50 wt % of Sm, 10-45 wt % of Fe, 1-10 wt % of Cu, 0.5-5 wt % of Zr, and the balance of Co, quenching the melt by a strip casting technique, to form a rare earth alloy strip containing at least 20% by volume of equiaxed crystals with a grain size of 1-200 &mgr;m and having a gage of 0.05-3 mm, and heat treating the strip in a non-oxidizing atmosphere at 1000-1300° C. for 0.5-20 hours, followed by aging treatment and grinding.

Abstract: A rare-earth alloy ingot is produced by melting an alloy composed of 20-30 wt % of a rare-earth constituent which is Sm alone or at least 50 wt % Sm in combination with at least one other rare-earth element, 10-45 wt % of Fe, 1-10 wt % of Cu and 0.5-5 wt % of Zr, with the balance being Co, and quenching the molten alloy in a strip casting process. The strip-cast alloy ingot has a content of 1-200 &mgr;m size equiaxed crystal grains of at least 20 vol % and a thickness of 0.05-3 mm. Rare-earth sintered magnets made from such alloys exhibit excellent magnetic properties and can be manufactured under a broad optimal temperature range during sintering and solution treatment.

Abstract: A sintered rare earth magnet consisting essentially of 20-30% by weight of R (wherein R is Sm or a mixture of Sm and another rare earth element), 10-45% by weight of Fe, 1-10% by weight of Cu, 0.5-5% by weight of Zr, and the balance of Co has on its surface a composite layer containing Sm2O3 and/or CoFe2O4 in Co or Co and Fe. The magnet is resistant to hydrogen embrittlement.

Abstract: An alloy powder for bonded rare earth magnets is prepared by melting an alloy consisting essentially of 20-30 wt % of Sm or a mixture of rare earth elements (inclusive of Y) containing at least 50 wt % of Sm, 10-45 wt % of Fe, 1-10 wt % of Cu, 0.5-5 wt % of Zr, and the balance of Co, quenching the melt by a strip casting technique, to form a rare earth alloy strip containing at least 20% by volume of equiaxed crystals with a grain size of 1-200 &mgr;m and having a gage of 0.05-3 mm, and heat treating the strip in a non-oxidizing atmosphere at 1000-1300° C. for 0.5-20 hours, followed by aging treatment and grinding.

Abstract: A sintered rare earth magnet consisting essentially of 20-30% by weight of R (wherein R is Sm or a mixture of Sm and another rare earth element), 10-45% by weight of Fe, 1-10% by weight of Cu, 0.5-5% by weight of Zr, and the balance of Co has on its surface a composite layer containing Sm2O3 and/or CoFe2O4 in Co or Co and Fe. The magnet is resistant to hydrogen embrittlement.