FORMING A SURFACE LAYER OF A CERAMIC MATRIX COMPOSITE ARTICLE

• US 20160214907A1
• Filed: 01/25/2016
• Published: 07/28/2016
• Est. Priority Date: 01/27/2015
• Status: Active Grant

• 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: Thibault, Robert Wesley, Shim, Sungbo, Shinavski, Robert, Lee, Kang N.
• Granted Patent: US 10,399,911 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: C04B 2235/612 Machining
• CPC Class Codes: C04B 2235/616 Liquid infiltration of green bodies or pre-forms
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/945 Products containing grooves, cuts, recesses or protusions
• CPC Class Codes: C04B 2235/95 Products characterised by their size, e.g. microceramics
• CPC Class Codes: C04B 2237/062 based on silica or silicates
• CPC Class Codes: C04B 2237/08 Non-oxidic interlayers
• CPC Class Codes: C04B 2237/083 Carbide interlayers, e.g. silicon carbide interlayers
• CPC Class Codes: C04B 2237/127 The active component for bonding being a refractory metal
• CPC Class Codes: C04B 2237/128 The active component for bonding being silicon
• CPC Class Codes: C04B 2237/16 Silicon interlayers
• CPC Class Codes: C04B 2237/34 Oxidic
• CPC Class Codes: C04B 2237/341 Silica or silicates
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 2237/346 Titania or titanates
• CPC Class Codes: C04B 2237/348 Zirconia, hafnia, zirconates or hafnates
• CPC Class Codes: C04B 2237/38 Fiber or whisker reinforced
• CPC Class Codes: C04B 2237/61 Joining two substrates of which at least one is porous by infiltrating the porous substrate with a liquid, such as a molten metal, causing bonding of the two substrates, e.g. joining two porous carbon substrates by infiltrating with molten silicon
• 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 35/62625 : Wet mixtures
• CPC Class Codes: C04B 35/62655 : Drying, e.g. freeze-drying, spray-drying, microwave or supercritical drying
• 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 41/4511 : using temporarily supports, e.g. decalcomania transfers or mould surfaces
• CPC Class Codes: C04B 41/4523 : applied from the molten state vitreous materials C04B41/5022; Thermal spraying, e.g. plasma spraying
• CPC Class Codes: C04B 41/4539 : as a emulsion, dispersion or suspension
• 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 41/4558 : Coating or impregnating involving the chemical conversion of an already applied layer, e.g. obtaining an oxide layer by oxidising an applied metal layer
• CPC Class Codes: C04B 41/4572 : Partial coating or impregnation of the surface of the substrate
• CPC Class Codes: C04B 41/4578 : Coating or impregnating of green ceramics or unset concrete
• CPC Class Codes: C04B 41/4584 : Coating or impregnating of particulate or fibrous ceramic material C04B20/10, C04B35/628 take precedence
• CPC Class Codes: C04B 41/5024 : Silicates C04B41/5022 takes precedence; silico-fluorides C04B41/5018
• CPC Class Codes: C04B 41/5027 : Oxide ceramics in general; Specific oxide ceramics not covered by C04B41/5029 - C04B41/5051
• CPC Class Codes: C04B 41/5035 : Silica
• CPC Class Codes: C04B 41/5045 : Rare-earth oxides
• CPC Class Codes: C04B 41/5059 : Silicon carbide
• 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 41/53 : involving the removal of at least part of the materials of the treated article, e.g. etching, drying of hardened concrete C04B41/0036 - C04B41/0054 take precedence
• CPC Class Codes: C04B 41/81 : Coating or impregnation
• CPC Class Codes: C04B 41/85 : with inorganic materials
• CPC Class Codes: C04B 41/89 : for obtaining at least two superposed coatings having different compositions

Abstract

The disclosure describes techniques for forming a surface layer of an article including a CMC using a cast. In some examples, the surface layer includes three-dimensional surface features, which may increase adhesion between the CMC and a coating on the CMC. In some examples, the surface layer may include excess material, with or without three-dimensional surface features, which is on the CMC. The excess material may be machined to remove some of the excess material and facilitate conforming the article to dimensional tolerances, e.g., for fitting the article to another component. The excess material may reduce a likelihood that the CMC (e.g., reinforcement material in the CMC) is damaged by the machining.

Claims

1. A method comprising:

depositing a slurry on a surface of an impregnated porous preform using a cast to form a surface layer including a plurality of three-dimensional surface features, wherein the cast defines the negative of the three-dimensional surface features, and wherein the impregnated porous preform comprises a reinforcement material and at least one matrix precursor;

drying the slurry to form a greenbody preform; and

infiltrating the greenbody preform with a molten infiltrant to form a composite article including the three-dimensional surface features.

2. The method of claim 1, wherein:

the slurry comprises a first slurry; and

the method further comprises, prior to depositing the first slurry on the surface of the impregnated porous preform;

impregnating a porous preform with a second slurry; and

drying the second slurry to form the impregnated porous preform.

3. The method of claim 2, wherein a composition of the first slurry is different than a composition of the second slurry.

4. The method of any claim 1, wherein depositing the slurry on the surface of the impregnated porous preform using the cast to form the surface layer including the plurality of three dimensional features comprises stamping the slurry on the surface of the impregnated porous preform using the cast to form the surface layer including the plurality of three dimensional features.

5. The method of claim 1, wherein the three-dimensional surface features comprise at least one of depressions, grooves, ridges, or protrusions.

6. The method of claim 1, wherein the plurality of three-dimensional surface features extend over only part of the surface.

7. The method of claim 1, further comprising forming a bond coating on the surface layer including the plurality of three-dimensional surface features, wherein the bonding coat comprises silicon.

8. The method of claim 1, further comprising forming an environmental barrier coating on the surface layer including the plurality of three-dimensional surface features, wherein the environmental barrier coating comprises at least one of barium strontium aluminosilicate, strontium aluminosilicate, barium aluminosilicate, a rare earth disilicate, or a rare earth monosilicate.

9. The method of claim 8, further comprising forming a CMAS-resistant coating on the environmental barrier coating, wherein the CMAS-resistant coating comprises a rare earth oxide, silica, and an alkali oxide and is essentially free of zirconia and hafnia.

10. The method of claim 1, further comprising forming an abradable coating on the surface layer including the plurality of three-dimensional surface features, wherein the abradable coating comprises at least one of barium strontium aluminosilicate, strontium aluminosilicate, barium aluminosilicate, a rare earth disilicate, or a rare earth monosilicate, and wherein the abradable coating comprises porosity between about 10 vol. % and about 50 vol. %.

11. The method of claim 1, further comprising:

3D printing a master mold defining the geometry of the three-dimensional surface features; and

forming the cast from as the negative of the master mold.

12. A method comprising:

impregnating a porous preform with a slurry to form an impregnated porous preform including a surface layer including a plurality of three-dimensional surface features, wherein the shapes of respective three-dimensional surface features the plurality of three-dimensional surface features are defined by a cast;

drying the slurry to form a greenbody preform; and

infiltrating the greenbody preform with a molten infiltrant to form a composite article including the three-dimensional surface features.

13. The method of claim 12, wherein the three-dimensional surface features comprise at least one of depressions, grooves, ridges, or protrusions.

14. The method of claim 12, wherein the plurality of three-dimensional surface features extend over only part of the surface.

15. The method of claim 12, further comprising forming a bond coating on the surface layer including the plurality of three-dimensional surface features, wherein the bonding coat comprises silicon.

16. The method of claim 12, further comprising forming an environmental barrier coating on the surface layer including the plurality of three-dimensional surface features, wherein the environmental barrier coating comprises at least one of barium strontium aluminosilicate, strontium aluminosilicate, barium aluminosilicate, a rare earth disilicate, or a rare earth monosilicate.

17. The method of claim 12, further comprising forming an abradable coating on the surface layer including the plurality of three-dimensional surface features, wherein the abradable coating comprises at least one of barium strontium aluminosilicate, strontium aluminosilicate, barium aluminosilicate, a rare earth disilicate, or a rare earth monosilicate, and wherein the abradable coating comprises porosity between about 10 vol. % and about 50 vol. %.

18. The method of claim 16, further comprising forming a CMAS-resistant coating on the environmental barrier coating, wherein the CMAS-resistant coating comprises a rare earth oxide, silica, and an alkali oxide and is essentially free of zirconia and hafnia.

19. The method of claim 12, further comprising:

3D printing a master mold defining the geometry of the three-dimensional surface features; and

forming the cast from as the negative of the master mold.

20. An assembly comprising:

a flexible cast;

an impregnated porous preform, wherein the impregnated porous preform comprises a reinforcement material and at least one matrix precursor, and wherein the flexible cast is adjacent to a surface of the impregnated porous preform; and

a slurry in space between the flexible cast and the surface of the impregnated porous preform.

21. The assembly of claim 20, wherein the cast defines a plurality of three-dimensional surface features comprising at least one of depressions, grooves, ridges, or protrusions.

22. The assembly of claim 20, wherein the cast comprises silicon or polyurethane.