Methods for manufacturing fuel cell interconnects using 3D printing

Patent metadata

Field	Value
Publication number	US-11962041-B2
Application number	US-202117221147-A
Country	US
Kind code	B2
Filing date	Apr 2, 2021
Priority date	Apr 3, 2020
Publication date	Apr 16, 2024
Grant date	Apr 16, 2024

Abstract

A method of forming a fuel cell interconnect includes depositing a Cr alloy powder, sintering the Cr alloy powder, and repeating the depositing and the sintering to form the fuel cell interconnect. The Cr alloy powder may include a pre-alloyed powder containing from about 4 wt. % to about 6 wt. % Fe, and from about 94 wt. % to about 96 wt. % Cr.

First claim

What is claimed is:

1. A method of forming a fuel cell interconnect, comprising:
depositing a Cr alloy powder;
sintering the Cr alloy powder;
repeating the depositing and the sintering to form the fuel cell interconnect comprising fuel-side ribs that at least partially define fuel channels;
depositing a Fe-rich powder on a fuel side of the interconnect; and
selectively sintering the Fe-rich powder to selectively form Fe-rich regions only on tops of fuel-side ribs, wherein:
the Cr alloy powder comprises pre-alloyed chromium iron alloy particles containing:
from about 4 wt. % to about 6 wt. % Fe; and
from about 94 wt. % to about 96 wt. % Cr, and

the Fe-rich powder has a higher Fe content than the Cr alloy powder and comprises pre-alloyed Cr—Fe alloy particles containing 25 wt. % to 75 wt. % Fe and balance Cr.

2. The method of claim 1 , wherein the sintering the Cr alloy powder comprises using at least one laser source to laser sinter the Cr alloy powder.

3. The method of claim 2 , wherein the sintering the Cr alloy powder comprises irradiating the Cr alloy powder with a laser beam in an inert atmosphere.

4. The method of claim 3 , wherein the inert atmosphere comprises an argon atmosphere.

5. The method of claim 2 , further comprising oxidizing the interconnect.

6. The method of claim 5 , wherein the oxidizing comprises heating the interconnect in an oxidizing atmosphere.

7. The method of claim 6 , wherein:
the oxidizing atmosphere comprises oxygen; and
the heating comprises rapid thermal oxidation.

8. The method of claim 6 , wherein:
the oxidizing atmosphere comprises oxygen; and
the heating comprises furnace heating.

9. The method of claim 5 , wherein the sintering the Cr alloy powder and the oxidizing are performed concurrently during a same step.

10. The method of claim 9 , wherein the concurrent sintering and oxidizing step comprises irradiating the Cr alloy powder with a laser beam in an atmosphere comprising an oxidant which oxidizes the Cr alloy powder.

11. The method of claim 10 , wherein the atmosphere consists essentially of argon and oxygen.

12. The method of claim 1 , wherein the interconnect further comprises-air-side ribs that at least partially define air channels.

13. The method of claim 1 , wherein the step of selectively sintering the Fe-rich powder comprises selective laser sintering.

14. The method of claim 1 , wherein the Fe-rich powder comprises a pure iron powder.

15. The method of claim 1 , wherein the Fe-rich powder comprises a mixture of pure iron and pure chromium powders, and wherein the mixture contains at least 10 wt. % iron and balance Cr.

16. The method of claim 1 , wherein the interconnect further comprises a fuel inlet hole and a fuel outlet hole.

17. The method of claim 1 , further comprising placing the interconnect into a solid oxide fuel cell stack.

18. A method of forming a fuel cell interconnect, comprising:
depositing a pre-alloyed Cr—Fe alloy powder comprising from about 4 wt. % to about 6 wt. % Fe;
sintering the Cr—Fe alloy powder;
repeating the depositing and the sintering to form the fuel cell interconnect comprising fuel-side ribs that at least partially define fuel channels;
depositing a Fe-rich pre-alloyed Cr—Fe powder comprising 25 wt. % to 75 wt. % Fe on a fuel side of the interconnect; and
using at least one laser source to selectively sinter the Fe-rich pre-alloyed Cr—Fe powder to selectively form Fe-rich regions only on tops of the fuel-side ribs.

Assignees

• Bloom Energy Corp

Inventors

• Verma Avinash
• Karuppaiah Chockkalingam
• Herchen Harald
• Lin Cheng-Yu
• Perry Martin

Classifications

• H01M50/522 Primary

  Inorganic material · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B22F10/50

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

• B22F10/62

  by chemical means · CPC title

• B33Y40/20

  Post-treatment, e.g. curing, coating or polishing · CPC title