Systems and methods for ceramic matrix composites

Patent metadata

Field	Value
Publication number	US-10427984-B2
Application number	US-201815874284-A
Country	US
Kind code	B2
Filing date	Jan 18, 2018
Priority date	Sep 5, 2014
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

Methods for fabricating a ceramic matrix composite are disclosed. A fiber preform may be placed in a mold. An aqueous solution may be added to the fiber preform. The aqueous solution may include water, carbon nanotubes, and a binder. The preform may be frozen. Freezing the preform may cause the water to expand and separate fibers in the fiber preform. The carbon nanotubes may bond to the fibers. The preform may be freeze dried to remove the water. The preform may then be processed according to standard CMC process.

First claim

The invention claimed is:

1. A ceramic matrix composite formed by a process comprising:
inserting a fiber tow in a mold;
introducing an aqueous solution comprising water, carbon nanotubes, and a binder into the mold;
freezing the aqueous solution, wherein the freezing the aqueous solution separates fibers within the fiber tow;
freeze drying the aqueous solution, wherein the freeze drying removes the water from the mold;
heat treating the fiber tow in the presence of a boron-bearing precursor and nitrogen gas to produce boron nitride nanotubes; and
processing the mold via at least one of slurry casting, chemical vapor infiltration, polymer infiltration and pyrolysis, or melt infiltration.

2. The ceramic matrix composite of claim 1 , wherein the carbon nanotubes are bonded to the fibers.

3. The ceramic matrix composite of claim 1 , wherein the carbon nanotubes form an interfacial region surrounding the fibers.

4. The ceramic matrix composite of claim 1 , wherein the boron-bearing precursor is boron oxide.

5. The ceramic matrix composite of claim 4 , wherein the heat treating the fiber tow proceeds through the reaction B 2 O 3 +3C(CNTs)+N 2 →2BN(BNNTs)+3CO, wherein CNTs represent carbon nanotubes, and BNNTs represent boron nitride nanotubes.

Assignees

• United Technologies Corp

Inventors

• Sheedy Paul
• Jarmon David C

Classifications

• C04B2235/5284

  Hollow fibers, e.g. nanotubes · CPC title

• C04B2235/3418

  Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint · CPC title

• C04B35/83

  Carbon fibres in a carbon matrix · CPC title

• C04B35/80

  Fibres, filaments, whiskers, platelets, or the like · CPC title

• C04B2235/606

  Drying · CPC title