Rare earth/iron/boron-based permanent magnet and method for the preparation thereof
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsKen Ohashi, Tadao Nomura
Life of this patent
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Abstract
Disclosed is a method for the preparation of a magnetically anisotropic rare earth/iron/boron-based permanent magnet in a relatively bulky form having a nanocomposite structure as prepared from quenched thin ribbons of the alloy. The method comprises heating the powder of quenched thin ribbons to a temperature allowing partial formation of a liquid phase of a lanthanum/iron or rare earth/copper alloy of low melting point and subjecting the powder of the quenched thin ribbons to a uniaxial hot-deformation treatment by passing the powder under resistance heating through a gap between a pair of compression rollers.
Claims7
A method for the preparation of a magnetically anisotropic rare earth-based permanent magnet having a composition comprising a rare earth element, iron and boron, of which the content of iron is at least 82% by moles, and having a nanocomposite structure of which the magnetically hard phase is R2Fe4B, in which R is a rare earth element, and the magnetically soft phase is Fe or Fe3B, which comprises the steps of:
- (a) heating a quenched thin ribbon of a rare earth-based alloy having a composition comprising a rare earth element or a combination of rare earth elements, iron or a combination of iron and cobalt and boron, of which the content of iron or the combination of iron and cobalt is at least 82% by moles, at a temperature allowing partial formation of a liquid phase;
- and
- (b) subjecting the quenched thin ribbon of a rare earth-based alloy under heating to a uniaxial hot-deformation treatment under a compressive force.
A method for the preparation of a magnetically anisotropic rare earth-based permanent magnet having a composition comprising a rare earth element, iron and boron, of which the content of iron is at least 82% by moles, and having a nanocomposite structure of which the magnetically hard phase is R2Fe4B, in which R is a rare earth element, and the magnetically soft phase is Fe or Fe3B, which comprises the steps of:
- (a) heating a quenched thin ribbon of a rare earth-based alloy having a composition comprising a rare earth element or a combination of rare earth elements, iron or a combination of iron and cobalt and boron, of which the content of iron or the combination of iron and cobalt is at least 82% by moles, at a temperature allowing partial formation of a liquid phase;
- and
- (b) subjecting the quenched thin ribbon of a rare earth-based alloy under heating to a uniaxial hot-deformation treatment under a compressive force in which the uniaxial hot-deformation treatment of the quenched thin ribbon is conducted by a method of current-carrying powder-pressing in which a powder of the quenched thin ribbon is passed through a gap between a pair of rollers under compression forming a layer of the powder with an electric current passing through the layer of the powder to effect resistance heating of the powder layer.
Dependencies are inferred from the claim text.