Aqueous braze paste

Patent metadata

Field	Value
Publication number	US-2016244374-A1
Application number	US-201615051203-A
Country	US
Kind code	A1
Filing date	Feb 23, 2016
Priority date	Feb 23, 2015
Publication date	Aug 25, 2016
Grant date	—

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.

2 . The method of claim 1 , wherein the aqueous braze paste includes a greater weight percent of the water than the water-soluble polymeric binder.

3 . The method of claim 1 , wherein the water-soluble alcohol based binder comprises at least one of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), or polyvinylpyrrolidone/vinyl acetate (PVP/VA) copolymer.

4 . 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.

5 . 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.

6 . The method of claim 1 , 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.

7 . 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.

8 . The method of claim 1 , wherein the adhesive comprises the aqueous braze paste or the water-soluble polymeric binder without the silicon-based alloy powder.

9 . 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.

10 . 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.

11 . 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.

12 . The paste of claim 11 , wherein the aqueous braze paste includes a greater weight percent of the water than the water-soluble polymeric binder.

13 . The paste of claim 11 , wherein the water-soluble polymeric binder comprises at least one of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), or polyvinylpyrrolidone/vinyl acetate (PVP/VA) copolymer.

14 . The paste 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.

15 . The paste of claim 11 , further comprising one or more additional components having a melting temperature greater than about 1400 degrees Celsius.

16 . The paste of claim 11 , 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.

17 . 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.

18 . The assembly of claim 17 , wherein the aqueous braze paste includes a greater weight percent of the water than the water-soluble polymeric binder.

19 . The assembly of claim 17 , wherein the water-soluble polymeric binder comprises at least one of polyvinyl alcohol(PVA), polyvinylpyrrolidone (PVP), or polyvinylpyrrolidone/vinyl acetate (PVP/VA) copolymer.

20 . The assembly of claim 17 , 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.

Assignees

• Rolls Royce Corp

Inventors

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

Classifications

• C04B35/63444

  Nitrogen-containing polymers, e.g. polyacrylamides, polyacrylonitriles, polyvinylpyrrolidone [PVP], polyethylenimine [PEI] · CPC title

• C04B35/63416

  Polyvinylalcohols [PVA]; Polyvinylacetates · CPC title

• C04B35/6316

  Binders based on silicon compounds · CPC title

• C04B37/008 Primary

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

• C04B2237/385

  Carbon or carbon composite · CPC title