IP Library Granted Patent US 9,005,780
Granted Patent B2
US 9,005,780 · App. 10/594,437 · Granted Apr 14, 2015

Rare earth magnet, method for producing same and method for producing multilayer body

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Quick Facts
Patent No.
US 9,005,780
App. No.
10/594,437
Granted
Apr 14, 2015
Kind
B2
Abstract

The present invention aims to provide a rare earth magnet having sufficiently excellent anticorrosion property. The rare earth magnet 1 according to the present invention to solve the above problems includes a magnet body 10 containing rare earth elements, a substantial amorphous layer 20 formed on a surface of the magnet body 10 , and a protecting layer 30 on a surface of the amorphous layer 20 , and the amorphous layer 20 contains material identical to main component elements of magnet material contained in the magnet body 10.

Claims (12)

1. A rare earth magnet comprising:

a magnet body containing a rare earth element;

an amorphous layer formed on a surface of the magnet body and containing amorphous substance; and

a protecting layer formed on a surface of the amorphous layer, wherein

the magnet body is polycrystalline and contains polycrystal substance,

a boundary between the magnet body and the amorphous layer includes a region where the polycrystal substance of the magnet body and the amorphous substance of the amorphous layer are mixed,

the amorphous layer has a film thickness from 0.3 to 10 μm,

the protecting layer consists of aluminum,

the amorphous layer is amorphized from a surface of the magnet body and contains an element identical to a main component element of a magnet material contained in the magnet body,

a roughness Ra of a boundary between the magnet body and the amorphous layer ranges from 1.27 to 1.45 μm,

a roughness Ra of a boundary between the amorphous layer and the protecting layer ranges from 0.68 to 0.85 μm, and

a coefficient of thermal expansion of the magnet body is substantially similar to a coefficient of thermal expansion of the amorphous layer.

Assignments (2)
CHANGE OF ADDRESS Recorded Jun 12, 2013
From: TDK CORPORATION
To: TDK CORPORATION
Reel/Frame 030651/0687 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 11, 2006
From: SAKAMOTO, TAKESHI; MORI, MASAMI; TANAKA, YOSHITOMO; MIWA, MASASHI
To: TDK CORPORATION
Reel/Frame 018622/0248 →