Method of heat-treating additively manufactured ferromagnetic components

Patent metadata

Field	Value
Publication number	US-10946444-B2
Application number	US-201815949551-A
Country	US
Kind code	B2
Filing date	Apr 10, 2018
Priority date	Apr 10, 2018
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

A method of heat-treating an additively-manufactured ferromagnetic component is presented and a related ferromagnetic component is presented. A saturation flux density of a heat-treated ferromagnetic component is greater than a saturation flux density of an as-formed ferromagnetic component. The heat-treated ferromagnetic component is further characterized by a plurality of grains such that at least 25% of the plurality of grains have a median grain size less than 10 microns and 25% of the plurality of grains have a median grain size greater than 25 microns.

First claim

The invention claimed is:

1. A method, comprising:
heat-treating an additively manufactured ferromagnetic component such that a saturation flux density of a heat-treated ferromagnetic component is greater than a saturation flux density of an as-formed ferromagnetic component, wherein the heat-treated ferromagnetic component is further characterized by a plurality of grains such that at least 25% of the plurality of grains have a median grain size less than 10 microns and 25% of the plurality of grains have a median grain size greater than 25 microns.

2. The method of claim 1 , wherein the additively manufactured ferromagnetic component comprises a metal alloy comprising iron and cobalt.

3. The method of claim 2 , wherein the metal alloy further comprises silicon, vanadium, or a combination thereof.

4. The method of claim 1 , wherein the saturation flux density of the heat- treated ferromagnetic component is greater than 2 Tesla.

5. The method of claim 1 , wherein an unsaturated relative permeability of the heat-treated ferromagnetic component is greater than 2500.

6. The method of claim 1 , wherein the as-formed ferromagnetic component has a median grain size less than or equal to about 5 microns and the heat-treated ferromagnetic component has a median grain size greater than or equal to about 20 microns.

7. The method of claim 1 , wherein the heat-treated ferromagnetic component has a median grain size in a range from about 10 microns to about 25 microns.

8. The method of claim 1 , wherein the additively manufactured ferromagnetic component is heat treated at a temperature in a range from 900° C. to about 1200° C.

9. The method of claim 1 , wherein heat-treating is performed during at least one build step of an additive manufacturing process used to form the additively manufactured ferromagnetic component, wherein a directed energy source is used during the at least one build step of the additive manufacturing process.

10. The method of claim 9 , wherein heat-treating is performed using the same directed energy source used during the at least one build step of the additive manufacturing process.

11. The method of claim 1 , wherein different portions of the additively manufactured ferromagnetic component are selectively heat treated to achieve determined saturation flux density and tensile strength values in these portions.

12. The method of claim 1 , wherein the additively manufactured ferromagnetic component is at least a portion of an electrical machine component.

13. A method, comprising:
heat-treating an additively manufactured ferromagnetic component such that a saturation flux density of a heat-treated ferromagnetic component is greater than a saturation flux density of an as-formed ferromagnetic component, wherein the heat-treated ferromagnetic component is further characterized by a plurality of grains such that at least 25% of the plurality of grains have a median grain size less than 10 microns and 25% of the plurality of grains have a median grain size greater than 25 microns, wherein different portions of the additively manufactured ferromagnetic component are selectively heat treated to achieve determined saturation flux density and tensile strength values in these portions, wherein the heat-treating includes holding the additively manufactured ferromagnetic component at a temperature greater than a ferrite-to-austenite transition temperature for at least 10 min.

14. The method of claim 13 , wherein the heat-treating is performed during at least one build step of an additive manufacturing process used to form the additively manufactured ferromagnetic component, wherein a directed energy source is used during the at least one build step of the additive manufacturing process.

15. The method of claim 14 , wherein the heat-treating is performed using the same directed energy source used during the at least one build step of the additive manufacturing process.

16. The method of claim 13 , wherein the saturation flux density of the heat-treated ferromagnetic component is greater than 2 Tesla.

17. A method, comprising:
heat-treating an additively manufactured ferromagnetic component such that a saturation flux density of a heat-treated ferromagnetic component is greater than a saturation flux density of an as-formed ferromagnetic component, wherein the heat-treated ferromagnetic component is further characterized by a plurality of grains such that at least 25% of the plurality of grains have a median grain size less than 10 microns and 25% of the plurality of grains have a median grain size greater than 25 microns, wherein the heat-treated ferromagnetic component has a unitary structure and a saturation flux density greater than 2 Tesla, wherein the heat-treating includes holding the additively manufactured ferromagnetic component at a temperature greater than a ferrite-to-austenite transition temperature, for at least 10 min.

18. The method of claim 17 , wherein an unsaturated relative permeability of the heat-treated ferromagnetic component is greater than 2500.

19. The method of claim 17 , wherein the additively manufactured ferromagnetic component comprises a metal alloy comprising iron and cobalt.

20. The method of claim 19 , wherein the metal alloy further comprises silicon, vanadium, or a combination thereof.

Assignees

• Gen Electric

Inventors

• Johnson Francis
• Osama Mohamed
• Jassal Anoop Kumar
• Adharapurapu Raghavendra Rao

Classifications

• B22F10/64

  by thermal means (control of energy beam parameters for post heating B22F10/364) · CPC title

• B22F10/50

  Treatment of workpieces or articles during build-up, e.g. treatments applied to fused layers during build-up · CPC title

• B22F10/38

  to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures · CPC title

• B22F10/364

  for post-heating, e.g. remelting · CPC title

• B22F10/25

  Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS] · CPC title