Brazing methods using porous interlayers and related articles

Patent metadata

Field	Value
Publication number	US-2022055133-A1
Application number	US-202117518734-A
Country	US
Kind code	A1
Filing date	Nov 4, 2021
Priority date	May 10, 2017
Publication date	Feb 24, 2022
Grant date	—

Abstract

The disclosure relates to a brazing method for joining substrates, in particular where one of the substrates is difficult to wet with molten braze material. The method includes formation of a porous metal layer on a first substrate to assist wetting of the first substrate with a molten braze metal, which in turn permits joining of the first substrate with a second substrate via a braze metal later in an assembled brazed joint. Ceramic substrates can be particularly difficult to wet with molten braze metals, and the disclosed method can be used to join a ceramic substrate to another substrate. The brazed joint can be incorporated into a solid-oxide fuel cell, for example as a stack component thereof, in particular when the first substrate is a ceramic substrate and the joined substrate is a metallic substrate.

First claim

1 .- 24 . (canceled)

25 . A brazed joint comprising:
(a) a first substrate; (b) a bulk second metal layer adjacent to the first substrate, the bulk second metal layer comprising a first metal and the second metal, the first metal being at a lower concentration than the second metal in the bulk second metal layer; (c) optionally a diffusion layer adjacent to the bulk second metal layer, the diffusion layer comprising the first metal and at least one component of a second substrate adjacent to the diffusion layer; and (d) a second substrate adjacent to the diffusion layer when the diffusion layer is present, or the bulk second metal layer when the diffusion layer is absent.

26 . The brazed joint of claim 25 , wherein:
the bulk second metal layer has a first metal concentration of 20 wt. % or less; and the diffusion layer is present and has a first metal concentration of at least 10 wt. % and greater than the first metal concentration of the bulk second metal layer.

27 . The brazed joint of claim 25 , wherein the bulk second metal layer has a second metal concentration ranging from 70 wt. % to 99 wt. %.

28 . The brazed joint of claim 25 , wherein the bulk second metal layer is substantially free from discrete first metal particles having a size greater than 1 μm.

29 . The brazed joint of claim 25 , wherein the diffusion layer is present and is substantially free from first metal particles.

30 . The brazed joint of claim 25 , wherein the diffusion layer is present and comprises the second metal at a concentration ranging from 1 wt. % to 30 wt. %.

31 . The brazed joint of claim 25 , wherein:
the first substrate comprises a ceramic material, and the second substrate comprises a metal material.

32 . The brazed joint of claim 31 , wherein the diffusion layer is present, and the component of the second substrate in the diffusion layer comprises a metallic component of the metal material at a concentration ranging from 5 wt. % to 80 wt. %.

33 . A method of assembling a solid-oxide fuel cell, the method comprising:
(a) providing the brazed joint of claim 25 , wherein the first substrate comprises a ceramic material, and the second substrate comprises a metal material; and (b) incorporating the brazed joint into a solid-oxide fuel cell as a stack component thereof.

34 . The brazed joint of claim 25 , wherein the second metal has a lower melting point than that of the first metal.

35 . The brazed joint of claim 25 , wherein the melting point of the second metal is lower than the melting point of the first metal by at least 300° C.

36 . The brazed joint of claim 25 , wherein the melting point of the second metal is lower than the melting point of the first metal by 300° C. to 700° C.

37 . The brazed joint of claim 25 , wherein the melting point of the second metal is lower than the melting point of the first metal by 700° C. to 1000° C.

38 . The brazed joint of claim 25 , wherein:
the first metal comprises at least one of nickel, aluminum, cobalt, iron, copper, and combinations thereof; and the second metal comprises at least one of silver, aluminum, tin, bismuth, nickel, copper, gold, cobalt, and combinations thereof.

39 . The brazed joint of claim 25 , wherein the second metal comprises silver.

40 . The brazed joint of claim 25 , wherein the first substrate comprises a ceramic material selected from the group consisting of aluminum oxide, zirconium oxide, cerium oxide, zinc oxide, silicon carbide, silicon nitride, tungsten carbide, and combinations thereof.

41 . The brazed joint of claim 25 , wherein the first substrate and the second substrate each comprise a metal material.

42 . The brazed joint of claim 25 , wherein the first substrate and the second substrate each comprise a different metal material.

43 . The brazed joint of claim 25 , wherein the first substrate and the second substrate each comprise at least one of a stainless steel alloy and a nickel-based high temperature alloy.

44 . The brazed joint of claim 25 , wherein the first substrate and the second substrate each comprise a different stainless steel alloy.

Assignees

• Univ Michigan State
• Delphi Tech Llc

Inventors

• Nicholas Jason Dale
• Zhou Quan
• Bieler Thomas Rector
• Kerr Rick Daniel

Classifications

• H01M8/1246

  the electrolyte consisting of oxides · CPC title

• B23K1/008

  Soldering within a furnace (B23K1/012 takes precedence) · CPC title

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• B23K1/0016 Primary

  Soldering of electronic components · CPC title

• H01M8/0282

  Inorganic material · CPC title