Methods for joining ceramic and metallic structures

Patent metadata

Field	Value
Publication number	US-2016172713-A1
Application number	US-201414572216-A
Country	US
Kind code	A1
Filing date	Dec 16, 2014
Priority date	Dec 16, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

A method for joining a ceramic component to a metallic component is described. At least one initial layer of an active metal is applied to one of the joining surfaces, by a cold spray technique. At least one second layer of a nickel-based braze composition is then applied over the initial layer by cold-spraying. The braze composition and components are then heated, so as to form an active braze joint between them. A method of sealing an open region of a sodium metal halide-based battery is also disclosed, using the brazing technique described herein to form braze joints that seal various components in the battery cells, such as metallic rings and ceramic collar structures.

First claim

What is claimed:

1 ) A method for joining a ceramic component to a metallic component, comprising the following steps:
a) applying at least one initial layer of an active metal onto one of the joining surfaces by a cold spray technique; b) applying at least one second layer of a nickel-based braze composition over the initial layer by the cold spray technique; and c) heating the braze composition and components to a sufficient brazing temperature, so as to provide an active braze joint between them.

2 ) The method of claim 1 , wherein each cold spray application is carried out a temperature that is less than the melting point of the composition being sprayed.

3 ) The method of claim 2 , wherein each cold spray application is carried out in an atmosphere comprising air, nitrogen, or helium.

4 ) The method of claim 2 , wherein each cold spray application is carried out in helium.

5 ) The method of claim 1 , wherein the thickness of the active metal layer is in the range of about 0.2 micron to about 20 microns.

6 ) The method of claim 1 , wherein the active metal is selected from the group consisting of titanium, zirconium, hafnium, and vanadium.

7 ) The method of claim 1 , wherein the active metal is titanium.

8 ) The method of claim 1 , wherein the braze composition for the second layer comprises at least about 30% by weight nickel.

9 ) The method of claim 8 , wherein the braze composition for the second layer further comprises at least one of silicon or boron.

10 ) The method of claim 9 , wherein the braze composition for the second layer further comprises at least one of niobium and chromium.

11 ) The method of claim 9 , wherein the braze composition further comprises at least one of iron or cobalt.

12 ) The method of claim 1 , wherein the active metal layer and second layer comprise a braze layer, said braze layer having a thickness in the range of about 5 microns to about 100 microns.

13 ) The method of claim 1 , wherein the nickel-based braze composition is applied in step 2, as a sequential series of cold spray depositions, wherein each deposition in the sequence is a deposition of one or more constituents of the braze composition.

14 ) The method of claim 13 , wherein the sequential series of depositions comprises a deposition of chromium; a deposition of nickel, and a deposition of at least one of silicon or boron.

15 ) The method of claim 1 , wherein the ceramic component is an alpha-alumina structure; and the metallic component is a structure comprising at least one of nickel, niobium, molybdenum, a nickel-cobalt ferrous alloy; mild steel, stainless steel, or tungsten, wherein both structures are incorporated into an electrochemical cell.

16 ) The method of claim 1 , wherein the ceramic and metal components each comprise at least one thermal battery structure selected from the group consisting of electrode compartments; sealing collar structures, sealing ring structures, and electrical current collectors.

17 ) A method of sealing an open region of a sodium metal halide-based battery that includes
(a) an anodic chamber for containing an anodic material; and a cathodic chamber for containing a cathodic material, separated from each other by an electrolyte separator tube, all contained within a case for the cell; (b) an electrically insulating ceramic collar positioned at or near an opening of the cathodic chamber, and defining an aperture in communication with the opening; and (c) a cathode current collector assembly disposed within the cathode chamber; said method comprising the steps of
(i) inserting at least one metal ring between at least a portion of the cathode current collector assembly and an adjacent portion of the ceramic collar;
(ii) applying at least one initial layer of an active metal onto at least part of the surface of the ceramic collar portion, by a cold spray technique;
(iii) applying at least one second layer of a nickel-based braze composition over the active metal layer by the cold spray technique; and
(iv) heating the braze composition to a sufficient brazing temperature, so as to provide, upon cooling, a hermetic seal between the metal ring, the current collector assembly, and the adjacent portion of the ceramic collar.

Assignees

• Gen Electric

Inventors

• Kumar Sundeep
• Calla Eklavya
• Rahmane Mohamed

Classifications

• H01M50/191

  Inorganic material · CPC title

• H01M50/184

  characterised by their shape or structure · CPC title

• H01M2300/0054

  Halogenides · CPC title

• B23K1/0016

  Soldering of electronic components · CPC title

• H01M10/399

  Cells with molten salts · CPC title