RARE-EARTH-IRON-BASED ALLOY MATERIAL

摘要

Provided are a powder for a magnet, which provides a rare-earth magnet having excellent magnet properties and which has excellent formability, a method for producing the powder for a magnet, a powder compact, a rare-earth-iron-based alloy material, and a rare-earth-iron-nitrogen-based alloy material which are used as materials for the magnet, and methods for producing the powder compact and these alloy materials.

主权项

1. A rare-earth-iron-based alloy material for a rare-earth magnet, the rare-earth-iron-based alloy material comprising:
a powder compact comprising:
magnetic particles each containing a hydride of a rare-earth element in an amount of less than 40% by volume and the balance being Fe;a phase of the hydride of the rare-earth element is adjacent to a phase consisting of pure Fe, andan interval between adjacent phases of the hydride of the rare-earth element with the phase of Fe provided therebetween is 3 μm or less, wherein:the phase of the hydride of the rare-earth element is granular,the granular hydride of the rare-earth element is dispersed in the phase of Fe,the rare-earth element is Sm, and the hydride of the rare-earth element consisting of Sm and hydrogen,an antioxidation layer is provided on the surface of each of the magnetic particles, the antioxidation layer including a low-oxygen-permeability layer composed of a material having an oxygen permeability coefficient at 30° C. of less than 1.0×10−11 m3·m/(s·m2·Pa) and a low-moisture-permeability layer composed of a material having a moisture permeability coefficient at 30° C. of less than 1000×10−13 kg/(m·s·MPa),the low-oxygen-permeability layer is polyester or polyvinyl chloride,the powder compact has a relative density of 85% or more, andthe rare-earth-iron-based alloy material is produced by heat-treating the powder compact in an inert atmosphere or in a reduced atmosphere.