Method for fabricating non-planar magnet

Patent metadata

Field	Value
Publication number	US-10460871-B2
Application number	US-201615290660-A
Country	US
Kind code	B2
Filing date	Oct 11, 2016
Priority date	Oct 30, 2015
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

A method for fabricating a non-planar magnet includes extruding a precursor material including neodymium iron boron crystalline grains into an original anisotropic neodymium iron boron permanent magnet having an original shape, wherein the original anisotropic neodymium iron boron permanent magnet has at least about 90 percent neodymium iron boron magnetic material by volume. The original anisotropic neodymium iron boron permanent magnet is heated to a deformation temperature. The original anisotropic neodymium iron boron permanent magnet is deformed into a reshaped anisotropic neodymium iron boron permanent magnet having a second shape substantially different from the original shape using heated tooling to apply a deformation load to the original anisotropic neodymium iron boron permanent magnet. The original anisotropic neodymium iron boron permanent magnet and the reshaped anisotropic neodymium iron boron permanent magnet each have respective magnetic moments substantially aligned with a respective local surface normal corresponding to the respective magnetic moment.

First claim

The invention claimed is:

1. A method for fabricating a non-planar magnet, comprising:
extruding a precursor material including neodymium iron boron crystalline grains into an original anisotropic neodymium iron boron permanent magnet having an original shape, wherein the original anisotropic neodymium iron boron permanent magnet has at least 90 percent neodymium iron boron magnetic material by volume;
heating the original anisotropic neodymium iron boron permanent magnet to a deformation temperature; and
deforming the original anisotropic neodymium iron boron permanent magnet into a reshaped anisotropic neodymium iron boron permanent magnet having a second shape substantially different from the original shape using heated tooling to apply a deformation load to the original anisotropic neodymium iron boron permanent magnet, wherein the original anisotropic neodymium iron boron permanent magnet and the reshaped anisotropic neodymium iron boron permanent magnet each have respective magnetic moments substantially aligned with a respective local surface normal corresponding to the respective magnetic moment.

2. The method as defined in claim 1 , further comprising dividing the reshaped anisotropic neodymium iron boron permanent magnet into a plurality of final anisotropic neodymium iron boron permanent magnets.

3. The method as defined in claim 1 wherein the deforming includes pressing the original anisotropic neodymium iron boron permanent magnet between a heated punch and a heated die.

4. The method as defined in claim 3 wherein the heated punch and the heated die together define a die cavity, wherein the die cavity defines at least an outer surface of the second shape.

5. The method as defined in claim 4 wherein:
an outer surface contour of the second shape defines a segment of a parabolic cylinder; or
the outer surface contour of the second shape defines at least a portion of an elliptic cylinder.

6. The method as defined in claim 4 wherein the original shape is an annular cylinder.

7. The method as defined in claim 6 , further including inserting a deformable core material into a core of the annular cylinder prior to the deforming to support the original anisotropic neodymium iron boron permanent magnet during the deforming into the reshaped anisotropic neodymium iron boron permanent magnet.

8. The method as defined in claim 6 wherein an outer surface contour of the second shape defines an elliptic cylinder.

9. The method as defined in claim 6 wherein an outer surface contour of the second shape defines two parabolic cylinders.

10. The method as defined in claim 1 wherein the deforming includes rolling between heated rollers.

11. The method as defined in claim 1 wherein a magnitude of an original cross-sectional area of the extruded precursor material normal to a transport direction during the extruding the precursor material is substantially unchanged in the second shape.

12. The method as defined in claim 1 wherein:
the deforming includes rolling between a first cylindrical roller having a first cylindrical roller diameter and a second cylindrical roller having a second cylindrical roller diameter;
a first tangential speed of the first cylindrical roller at the first cylindrical roller diameter is different from a second tangential speed of the second cylindrical roller at the second cylindrical roller diameter to transform the original anisotropic neodymium iron boron permanent magnet having the original shape into the reshaped anisotropic neodymium iron boron permanent magnet having the second shape;
the original shape is a rectangular prism; and
the second shape is a portion of a curved wall.

13. The method as defined in claim 1 wherein the deformation temperature is from about 450° C. to about 900° C.

14. The method as defined in claim 1 wherein the material comprising the original anisotropic neodymium iron boron permanent magnet flows under a deformation stress applied to the original anisotropic neodymium iron boron permanent magnet at the deformation temperature.

15. A method for fabricating a non-planar magnet, comprising:
heating a precursor material including neodymium iron boron crystalline grains to an extrusion temperature;
extruding the precursor material into an original anisotropic neodymium iron boron permanent magnet having an original shape, wherein the original anisotropic neodymium iron boron permanent magnet has at least 90 percent neodymium iron boron magnetic material by volume; and
deforming the original anisotropic neodymium iron boron permanent magnet into a reshaped anisotropic neodymium iron boron permanent magnet having a second shape substantially different from the original shape using tooling to apply a deformation load to the original anisotropic neodymium iron boron permanent magnet before the original anisotropic neodymium iron boron permanent magnet cools below a minimum deformation temperature;
wherein the extrusion temperature is from about 450° C. to about 900° C.;
and wherein the minimum deformation temperature is from about 450° C. to about 900° C.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Pinkerton Frederick E
• Sachdev Anil K

Classifications

• H02K1/276

  Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM] · CPC title

• B21D22/022

  by heating the blank or stamping associated with heat treatment (C21D takes precedence) · CPC title

• B21C35/023

  Work treatment directly following extrusion, e.g. further deformation or surface treatment  (B21C35/03 takes precedence; gas treatment B21C23/009) · CPC title

• B21C23/06

  Making sheets · CPC title

• H01F41/0266 Primary

  Moulding; Pressing (H01F41/0273 takes precedence; hard magnetic particles H01F1/06, H01F1/11) · CPC title