L10-FeNi magnetic powder and bond magnet

Patent metadata

Field	Value
Publication number	US-11244776-B2
Application number	US-201916672865-A
Country	US
Kind code	B2
Filing date	Nov 4, 2019
Priority date	May 17, 2017
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

An L10-FeNi magnetic powder has an average particle size of 50 nm to 1 μm, and an average value of sphericity P of 0.9 or more. The sphericity P is defined as P=Ls/Lr, where Lr is a perimeter of an L10-FeNi magnetic powder particle on an image of a microscope, and Ls is a perimeter of a perfect circle that has a same area as the L10-FeNi magnetic powder particle on the image for which Lr is calculated.

First claim

What is claimed is:

1. A bonded magnet comprising:
a base material; and
a magnetic powder dispersed in the base material,
wherein the magnetic powder includes:
an L10-FeNi magnetic powder having:
an average particle size of 50 nm to 1 μm; and
an average value of sphericity P of 0.9 or more,
wherein the sphericity P is defined as P=Ls/Lr,
where Lr is a perimeter of an L10-FeNi magnetic powder particle on an image of a microscope, and Ls is a perimeter of a perfect circle that has a same area as the L10-FeNi magnetic powder particle on the image for which Lr is calculated; and

a large-size magnetic powder having a different composition from the L10-FeNi magnetic powder and having an average particle size of 1 μm to 500 μm,
wherein a mass percent of the L10-FeNi magnetic powder in the magnetic powder is 5% or more.

2. The bonded magnet according to claim 1 , the average particle size of the L10-FeNi magnetic powder being in a range from 400 nm to 1 μm.

3. The bonded magnet according to claim 1 , wherein:
a filling ratio of the magnetic powder is 80 mass % or more.

4. The bonded magnet according to claim 1 , wherein:
the mass percent of the L10-FeNi magnetic powder in the magnetic powder is 10% or more.

Assignees

• Denso Corp

Inventors

• Kura Hiroaki
• Watanabe Eiji
• Kin Masane
• Osanai Kenta

Classifications

• H01F1/083 Primary

  in a bonding agent · CPC title

• H01F1/0551 Primary

  in the form of particles, e.g. rapid quenched powders or ribbon flakes · CPC title

• B22F1/054

  Nanosized particles · CPC title

• B22F1/052

  characterised by a mixture of particles of different sizes or by the particle size distribution · CPC title

• B22F3/00

  Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor {; Presses and furnaces} · CPC title