Anisotropic Rare Earths-Free Matrix-Bonded High-Performance Permanent Magnet Having A Nanocrystalline Structure, And Method For Production Thereof

Patent metadata

Field	Value
Publication number	US-2016372243-A1
Application number	US-201414901792-A
Country	US
Kind code	A1
Filing date	May 26, 2014
Priority date	Jul 12, 2013
Publication date	Dec 22, 2016
Grant date	—

Abstract

A method for producing a permanent magnet includes coating synthesized nanoparticles with a matrix by a by physical or physical-chemical deposition process, and introducing the matrix-coated nanoparticles into a mold, and exposing the matrix-coated nanoparticles in the mold to an external force field. High fill levels can be achieved in this manner.

First claim

What is claimed is:

1 . A method for producing a permanent magnet, comprising the steps of:
synthesizing rare-earth-free ferromagnetic anisotropic nanoparticles; coating the synthesized nanoparticles with a matrix using a physical or physicochemical deposition to generate a matrix coating of the nanoparticles; introducing the matrix-coated nanoparticles into a mold; and applying an external force field to orient and compress the matrix-coated nanoparticles in the mold.

2 . The method of claim 1 , wherein the deposition comprises physical vapor deposition, chemical vapor deposition, or thermal spraying.

3 . The method of claim 1 , wherein the matrix consists of a plastic.

4 . The method of claim 3 , wherein the plastic comprises a thermoplastic or a thermoset.

5 . The method of claim 3 , wherein the plastic is polyphenyl sulfide or polyamide or epoxide.

6 . (canceled)

7 . The method of claim 1 , wherein the nanoparticles have a core or a core-shell construction, wherein the shell completely or partly covers the core.

8 . The method of claim 1 , wherein the nanoparticles have a protective casing.

9 . The method of claim 1 , comprising, during the coating of the synthesized nanoparticles, using a fluidized bed to spatially distribute the nanoparticles.

10 . The method of claim 1 , wherein the synthesized nanoparticles are in powder form after being coated with the matrix.

11 . The method of claim 1 , wherein the steps of orienting and shaping the matrix-coated nanoparticles are performed simultaneously.

12 . The method of claim 1 , wherein the matrix coating solidifies or cures during or after shaping.

13 . The method of claim 12 , the solidifying or curing of the matrix coating comprises comprising a thermal activation.

14 . The method of claim 1 , wherein the nanoparticles at least one of (a) contain Co, Fe, Ni, or Mn or (b) are synthesized wet-chemically.

15 . The method of claim 7 , wherein the core consists of a soft-magnetic material and the shell of a hard-magnetic material, or vice versa.

16 . The method of claim 7 , wherein the protective casing consists of carbon and is generated by storage of the nanoparticles for a period of multiple hours and temperatures in a range of around 250° C. to 350° C. in an organic liquid.

17 . The method of claim 7 , wherein the protective casing consists of silicon dioxide and is generated by hydrolysis and polycondensation of silane compounds in a polar solvent.

18 . A permanent magnet generated a process including:
synthesizing rare-earth-free ferromagnetic anisotropic nanoparticles; coating the synthesized nanoparticles with a matrix using a physical or physicochemical deposition to generate a matrix coating of the nanoparticles; introducing the matrix-coated nanoparticles into a mold; and applying an external force field to orient and compress the matrix-coated nanoparticles in the mold.

19 . The method of claim 1 , wherein the deposition comprises ion beam-assisted deposition or sputtering, molecular beam epitaxy, electron beam evaporation, atomic layer deposition, or laser ablation.

Assignees

• Siemens Ag

Inventors

• Cassignol Caroline
• Krispin Michael
• Zins Inga

Classifications

• H01F41/0273

  Imparting anisotropy (methods and devices for magnetising permanent magnets H01F13/003) · CPC title

• H01F1/083

  in a bonding agent · CPC title

• H01F1/061 Primary

  with a protective layer · CPC title