MODIFIED ATMOSPHERE MELT INFILTRATION

• US 20160230570A1
• Filed: 02/10/2016
• Published: 08/11/2016
• Est. Priority Date: 02/11/2015
• Status: Abandoned Application

• Current Assignee: Rolls-Royce High Temperature Composites, Inc. (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce Corporation (Rolls-Royce Holdings Plc), Rolls-Royce High Temperature Composites, Inc. (Rolls-Royce Holdings Plc)
• Inventors: Harris, Stephen L., Kidd, Richard W., Shinavski, Robert J., Shim, Sungbo, Lee, Kang N.
• Application Number:
  US15/040,527
• Publication Number:
  US 20160230570A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C04B 2235/3826 Silicon carbides
• CPC Class Codes: C04B 2235/5276 Whiskers, spindles, needles or pins
• CPC Class Codes: C04B 2235/614 Gas infiltration of green bodies or pre-forms
• CPC Class Codes: C04B 2235/616 Liquid infiltration of green bodies or pre-forms
• CPC Class Codes: C04B 35/565 based on silicon carbide
• CPC Class Codes: C04B 35/573 obtained by reaction sintering or recrystallisation
• CPC Class Codes: C04B 35/58092 based on refractory metal silicides
• CPC Class Codes: C04B 35/584 based on silicon nitride
• CPC Class Codes: C04B 35/62857 with non-oxide ceramics
• CPC Class Codes: C04B 35/62863 Silicon carbide
• CPC Class Codes: C04B 35/62868 Boron nitride
• CPC Class Codes: C04B 35/62894 with more than one coating layer
• CPC Class Codes: C04B 35/80 Fibres, filaments, whiskers, platelets, or the like
• CPC Class Codes: C04B 35/806 The matrix of the ceramic products consisting of non-oxides only
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4527 Plasma spraying deposition from the gas phase using plasma C04B41/4533
• CPC Class Codes: C04B 41/4529 applied from the gas phase
• CPC Class Codes: C04B 41/4556 coating or impregnating with a product reacting with the substrate, e.g. generating a metal coating by surface reduction of a ceramic substrate
• CPC Class Codes: C04B 41/4582 Porous coatings, e.g. coating containing porous fillers
• CPC Class Codes: C04B 41/5024 Silicates C04B41/5022 takes precedence; silico-fluorides C04B41/5018
• CPC Class Codes: C04B 41/5059 : Silicon carbide
• CPC Class Codes: C04B 41/5096 : Silicon C04B35/573 takes precedence
• CPC Class Codes: C04B 41/52 : Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
• CPC Class Codes: C04B 41/89 : for obtaining at least two superposed coatings having different compositions
• CPC Class Codes: F01D 11/122 : with erodable or abradable material blades having cutting or grinding tips F01D5/20
• CPC Class Codes: F01D 5/282 : Selecting composite materials, e.g. blades with reinforcing filaments
• CPC Class Codes: F01D 5/284 : Selection of ceramic materials
• CPC Class Codes: F01D 5/288 : Protective coatings for blades
• CPC Class Codes: F05D 2240/11 : Shroud seal segments
• CPC Class Codes: F05D 2300/222 : Silicon
• CPC Class Codes: F05D 2300/2261 : of silicon
• CPC Class Codes: F05D 2300/6032 : Metal matrix composites [MMC]
• CPC Class Codes: F05D 2300/6033 : Ceramic matrix composites [CMC]

Abstract

A ceramic matrix composite component for use in a gas turbine engine and method for making the same are described herein. The component comprising a body and an outer region. The body having a silicon containing ceramic composite. The outer region on an outer surface of the body.

Claims

1. A ceramic matrix composite component for use in a gas turbine engine, the component comprising

a body comprising a silicon containing ceramic composite;

and

an outer region on an outer surface of the body, the outer region comprising whiskers embedded in a matrix, the whiskers comprising silicon carbide, and the matrix comprising a majority of silicon metal.

2. The component of claim 1, wherein the outer region further comprises precipitates selected from a group consisting of silicon carbide, iron-rich silicides, silicon borides, and any combination thereof.

3. The component of claim 1, wherein the outer region has a substantially flat external surface.

4. The component of claim 1, wherein the ceramic composite of the body is a silicon carbide-silicon carbide composite.

5. The component of claim 1, wherein the whiskers have a diameter of between about 0.5 μ

m and about 25 μ

m.

6. The component of claim 1, wherein the outer region has a thickness of between about 5 μ

m and about 300 μ

m.

7. The component of claim 1, wherein the matrix consists essentially of silicon metal.

8. The component of claim 7, wherein the silicon metal of the outer region is wetted to the silicon carbide whiskers.

9. The component of claim 1, further comprising an environmental barrier coating bonded to the outer region such that the outer region is sandwiched between the body the and environmental barrier coating.

10. The component of claim 9, wherein the environmental barrier coating is selected from a group consisting of mullite, barium strontinum aluminosilicate, strontinum aluminosilicate, barium aluminosilicate, rare earth disilicates, rare earth monosilicate, and any combination thereof.

11. The component of claim 10, further comprising an abradable bonded to the environmental barrier coating such that the environmental barrier is sandwiched between the ceramic matrix composite component and the abradable coating.

12. The component of claim 11, wherein the abradable is selected from a group consisting of barium strontinum aluminosilicate, strontinum aluminosilicate, barium aluminosilicate, rare earth disilicates, rare earth monosilicates, and combinations thereof.

13. An in situ method for forming a silicon rich outer region along a ceramic matrix composite component for use in a gas turbine engine, the method comprising

melt infiltrating a silicon metal or alloy into a ceramic preform to form a body;

cooling the component after the melt infiltrating;

adding hydrocarbon gas to an atmosphere in contact with the body during at least a portion of the melt infiltrating, the cooling or any combination thereof; and

chemically reacting the hydrocarbon gas with silicon in the body to form silicon carbide on an outer region of the body.

14. The method of claim 13, wherein the silicon carbide on the outer region of the body comprise whiskers.

15. The method of claim 13, further comprising wetting a silicon metal or alloy, formed from silicon of the body, to the whiskers to form the outer region, wherein the outer region has a silicon concentration greater than a silicon concentration of the body.

16. The method of claim 13, wherein the hydrocarbon gas is selected from a group consisting of methane, propane, or a combination thereof.

17. The method of claim 16, further comprising adding hydrogen gas to the step of adding hydrocarbon gas in a ratio of hydrocarbon gas to hydrogen gas of between about 4:

1 and about 1;

20.

18. The method of claim 13, further comprising depositing an environmental barrier coating along an external surface of an outer region.

19. The method of claim 18, further comprising depositing a porous abradable such that the environmental barrier coating is sandwiched between the outer region of the body and the abradable.

20. The method of claim 13, further comprising adding a catalyst comprising nickel, molybdenum, cobalt, or any combination thereof during the step of melt infiltration.