Aqueous braze paste

Patent metadata

Field	Value
Publication number	US-10183894-B2
Application number	US-201615051203-A
Country	US
Kind code	B2
Filing date	Feb 23, 2016
Priority date	Feb 23, 2015
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

In some examples, a method including positioning a first ceramic or ceramic matrix composite (CMC) part and a second ceramic or CMC part adjacent to each other to define a joint between adjacent portions of the first ceramic or CMC part and the second ceramic or CMC part; and depositing an aqueous braze paste at least one of in the joint or adjacent the joint, wherein the aqueous braze paste comprises water, a water-soluble polymeric binder, and a silicon-based powder alloy.

First claim

What is claimed is:

1. A method comprising:
positioning a first ceramic or ceramic matrix composite (CMC) part and a second ceramic or CMC part adjacent to each other to define a joint between adjacent portions of the first ceramic or CMC part and the second ceramic or CMC part; and
depositing an aqueous braze paste at least one of in the joint or adjacent the joint, wherein the aqueous braze paste comprises water, a water-soluble polymeric binder, and a silicon-based alloy powder, wherein the aqueous braze paste includes a greater weight percent of the water than the water-soluble polymeric binder, wherein the water-soluble polymeric binder comprises at least one of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), or polyvinylpyrrolidone/vinyl acetate (PVP/VA) copolymer, and wherein the aqueous braze paste comprises between about 4.25 wt % and about 24 wt % of the water, and between about 0.25 wt % and about 4 wt % of the water-soluble polymeric binder.

2. The method of claim 1 , wherein the silicon-based alloy powder comprises an alloying component, the alloying component comprising at least one of Ti, Co, C, Mo, B, V, Cr, Cu, Nb, or Zr.

3. The method of claim 1 , wherein the aqueous braze paste comprises one or more additional components having a melting temperature greater than about 1400 degrees Celsius.

4. The method of claim 1 , wherein positioning a first ceramic or CMC part and a second ceramic or CMC part adjacent to each other to define a joint between adjacent portions of the first ceramic or CMC part and the second ceramic or CMC part comprising fixturing the first ceramic or CMC part and the second ceramic or CMC part adjacent to each other via an adhesive.

5. The method of claim 4 , wherein the adhesive comprises the aqueous braze paste or the water-soluble polymeric binder without the silicon-based alloy powder.

6. The method of claim 1 , further comprising:
heating the aqueous braze paste to a temperature at which the aqueous braze paste flows in the joint; and
subsequently cooling the aqueous braze paste to form a braze joint attaching the first ceramic or CMC part and the second ceramic or CMC part adjacent to each other.

7. The method of claim 1 , wherein positioning the first ceramic or CMC part and a second ceramic or CMC part adjacent to each other to define a joint between adjacent portions of the first ceramic or CMC part and the second ceramic or CMC part comprises forming at least one of a bridle joint, a butt joint, a miter join, a dado joint, a groove joint, a tongue and groove joint, a mortise and tenon joint, a birdsmouth joint, a halved joint, a biscuit joint, a lap joint, a double lap joint, a dovetail joint, or a spliced joint.

8. An aqueous braze paste comprising water, a water-soluble polymeric binder, and a silicon-based alloy powder, wherein the braze paste is configured to connect a first ceramic or ceramic matrix composite (CMC) part and a second ceramic or CMC part adjacent to each other via a braze joint between adjacent portions of the first ceramic or CMC part and the second ceramic or CMC part, wherein the aqueous braze paste includes a greater weight percent of the water than the water-soluble polymeric binder, wherein the water-soluble polymeric binder comprises at least one of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), or polyvinylpyrrolidone/vinyl acetate (PVP/VA) copolymer, and wherein the aqueous braze paste comprises between about 4.25 wt % and about 24 wt % of the water, and between about 0.25 wt % and about 4 wt % of the water-soluble polymeric binder.

9. The paste of claim 8 , wherein the silicon-based alloy powder comprises an alloying component, the alloying component comprising at least one of Ti, Co, C, Mo, B, V, Cr, Cu, Nb, or Zr.

10. The paste of claim 8 , further comprising one or more additional components having a melting temperature greater than about 1400 degrees Celsius.

11. An assembly comprising:
a first ceramic or ceramic matrix composite (CMC) part;
a second ceramic or CMC part adjacent to the first ceramic or ceramic matrix composite part, wherein the parts define a joint between adjacent portions of the first ceramic or CMC part and the second ceramic or CMC part; and
an aqueous braze paste at least one of in the joint or adjacent the joint, wherein the aqueous braze paste comprises water, a water-soluble polymeric binder, and a silicon-based alloy powder, wherein the aqueous braze paste includes a greater weight percent of the water than the water-soluble polymeric binder, wherein the water-soluble polymeric binder comprises at least one of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), or polyvinylpyrrolidone/vinyl acetate (PVP/VA) copolymer, and wherein the aqueous braze paste comprises between about 4.25 wt % and about 24 wt % of the water, and between about 0.25 wt % and about 4 wt % of the water-soluble polymeric binder.

12. The assembly of claim 11 , wherein the silicon-based alloy powder comprises an alloying component, the alloying component comprising at least one of Ti, Co, C, Mo, B, V, Cr, Cu, Nb, or Zr.

13. The method of claim 1 , wherein the aqueous braze paste comprises between about 18 wt % and about 24 wt % of the water.

14. The method of claim 1 , wherein the aqueous braze paste comprises between about 0.25 wt % and about 2 wt % of the water-soluble polymeric binder.

15. The method of claim 1 , wherein the water-soluble polymeric binder comprises at least one of the polyvinylpyrrolidone (PVP), or the polyvinylpyrrolidone/vinyl acetate (PVP/VA) copolymer.

16. The paste of claim 8 , wherein the aqueous braze paste comprises between about 18 wt % and about 24 wt % of the water.

17. The paste of claim 8 , wherein the aqueous braze paste comprises between about 0.25 wt % and about 2 wt % of the water-soluble polymeric binder.

18. The paste of claim 8 , wherein the water-soluble polymeric binder comprises at least one of the polyvinylpyrrolidone (PVP), or the polyvinylpyrrolidone/vinyl acetate (PVP/VA) copolymer.

19. The assembly of claim 11 , wherein the aqueous braze paste comprises between about 18 wt % and about 24 wt % of the water.

20. The assembly of claim 11 , wherein the aqueous braze paste comprises between about 0.25 wt % and about 2 wt % of the water-soluble polymeric binder.

Assignees

• Rolls Royce Corp

Inventors

• Nelson Scott
• Landwehr Sean E
• Davis Joel
• Xu Raymond Ruiwen

Classifications

• C04B2237/128

  The active component for bonding being silicon · CPC title

• C04B2237/385

  Carbon or carbon composite · CPC title

• C04B37/008 Primary

  by means of an interlayer consisting of an organic adhesive, e.g. phenol resin or pitch · CPC title

• C04B37/006

  consisting of metals or metal salts · CPC title