Nanocomposite permanent magnets and methods of making the same

Patent metadata

Field	Value
Publication number	US-9373433-B2
Application number	US-201213538229-A
Country	US
Kind code	B2
Filing date	Jun 29, 2012
Priority date	Jun 29, 2012
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

A method of making a nanocomposite permanent magnet is provided. The method comprises applying an extreme shear deformation to hard magnetic phase nanoparticles and soft magnetic phase nanoparticles to align at least a portion of the hard phase magnetic particles and to produce a nanocomposite permanent magnet.

First claim

The invention claimed is:

1. A method of making a nanocomposite permanent magnet, comprising:
applying shear deformation to hard magnetic phase nanoparticles and soft magnetic phase nanoparticles to align at least a portion of the hard phase magnetic particles and to produce a nanocomposite permanent magnet
further comprising degassing the hard and soft magnetic phase nanoparticles prior to applying the shear deformation to form a degassed composite mixture of the hard magnetic phase nanoparticles and soft magnetic phase nanoparticles;
wherein the step of applying the shear deformation comprises;
disposing the degassed composite mixture in a ductile conduit;
degassing the ductile conduit;
sealing the ductile conduit after degassing;
disposing the ductile conduit in a deformation container; and
transmitting a shear strain to the ductile conduit via the deformation container to produce the nanocomposite permanent magnet.

2. The method of claim 1 , wherein the hard magnetic phase particles comprise samarium cobalt, neodymium iron boron, samarium iron nitrogen, iron platinum, cobalt platinum, iron palladium, cobalt palladium, aluminum nickel cobalt, barium-hexaferrite, strontium-hexaferrite, manganese bismuth, manganese aluminum,or combinations thereof.

3. The method of claim 1 , wherein the soft magnetic phase nanoparticles comprise iron, iron cobalt, iron silicon, iron nickel, and iron boron, or combinations thereof.

4. The method of claim 1 , wherein the hard magnetic phase nanoparticles comprise particles having an aspect ratio in a range from about 2:1 to about 100:1.

5. The method of claim 1 , wherein the soft magnetic phase nanoparticles are produced by chemically reducing salts of a soft magnetic phase material.

6. The method of claim 1 , further comprising pre-compacting the hard magnetic phase nanoparticles and soft magnetic phase nanoparticles prior to applying the shear deformation.

7. The method of claim 1 , comprising applying the shear deformation to a core-shell structure of the hard magnetic phase nanoparticles and soft magnetic phase nanoparticles, wherein the hard phase is disposed in the core and the soft phase is disposed in the shell.

8. The method of claim 1 , wherein the applying step further comprises applying the shear deformation to a blend of the hard magnetic phase nanoparticles and the soft magnetic phase nanoparticles.

9. The method of claim 8 , further comprising:
adding a first solvent and a first surfactant to particles of a hard phase magnetic material to form a mixture;
processing the mixture to form surfactant coated hard magnetic phase nanoparticles.

10. The method of claim 9 , wherein the step of processing comprises milling.

11. The method of claim 9 , further comprising:
adding a second solvent and a second surfactant to a blend of the surfactant coated hard magnetic phase nanoparticles and the soft magnetic phase nanoparticles;
milling the blend to form a composite mixture having a dispersion of the surfactant coated hard magnetic phase nanoparticles and the soft magnetic phase nanoparticles; and
degassing the composite mixture to remove at least portions of first and second solvents and surfactants.

12. The method of claim 1 , comprising:
compacting the degassed composite mixture by disposing the degassed composite mixture in a flexible container to form a compacted composite; and
cold isostatically pressing the flexible container.

13. The method of claim 1 , further comprising magnetically aligning the hard and soft magnetic phase nanoparticles prior to the step of degassing.

14. The method of claim 1 , wherein the step of transmitting the shear strain comprises applying one or more passes via equal channel angular extrusion, or via high pressure torsion, or both.

15. The method of claim 14 , comprising maintaining the same alignment of the ductile conduit during each pass.

16. The method of claim 1 , comprising altering an alignment of the ductile conduit by a determined angle after each pass.

17. The method of claim 1 , further comprising disintegrating the deformation container to obtain the nanocomposite permanent magnet.

18. The method of claim 1 , further comprising annealing the nanocomposite permanent magnet.

Assignees

• Johnson Francis
• Colborn Robert Edgar
• Marte Judson Sloan
• Bonitatibus Jr Peter John
• Kandapallil Binil Itty Ipe
• Haouaoui Mohammed
• Chen Christina
• Gen Electric

Inventors

• Johnson Francis
• Colborn Robert Edgar
• Marte Judson Sloan
• Bonitatibus Jr Peter John
• Kandapallil Binil Itty Ipe
• Haouaoui Mohammed
• Chen Christina

Classifications

• H01F1/068

  having a L10 crystallographic structure, e.g. [Co,Fe][Pt,Pd] (nano)particles · CPC title

• H01F1/10

  non-metallic substances, e.g. ferrites {, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure} · CPC title

• C22C1/02

  by melting {(C22C1/1036 takes precedence)} · CPC title

• H01F1/0576

  pressed, e.g. hot working · CPC title

• H01F1/0579 Primary

  with exchange spin coupling between hard and soft nanophases, e.g. nanocomposite spring magnets · CPC title