Method of fabricating cooling features on a ceramic matrix composite (CMC) component

1. A method of fabricating cooling features on a CMC component, the method comprising:

compressing a fabric preform within tooling including holes and/or recesses facing the fabric preform;

pushing portions of the fabric preform into the holes and/or recesses;

delivering gases through the tooling to deposit a matrix material on exposed surfaces of the fabric preform during the compression, the gases being delivered through channels in the tooling terminating in the holes and/or recesses, the matrix material building up on the portions of the fabric preform pushed into the holes and/or recesses, thereby forming a rigidized preform with surface protrusions;

removing the tooling; and

densifying the rigidized preform, thereby forming a CMC component including raised surface features.

2. The method of claim 1 , wherein the fabric preform comprises silicon carbide fibers and the matrix material comprises silicon carbide,

and wherein the CMC component includes a silicon carbide matrix reinforced with the silicon carbide fibers.

3. The method of claim 1 , wherein the gases include methyltrichlorosilane (CH 3 SiCl 3 ) and hydrogen gas (H 2 ).

4. The method of claim 1 , wherein the raised surface features comprise pedestals or ribs.

5. The method of claim 4 , wherein the pedestals have a cross-sectional shape selected from the group consisting of: circle, square, triangle, pentagon, and hexagon.

6. The method of claim 4 , wherein each of the ribs has a length-to-width aspect ratio of at least about 2.

7. The method of claim 6 , wherein the length-to-width aspect ratio is at least about 10.

8. The method of claim 4 , wherein the ribs are curved.

9. The method of claim 1 , wherein a spacing between the raised surface features is at least about 0.06 cm.

10. The method of claim 1 , wherein the raised surface features have a height within a range from about 0.03 cm to about 0.10 cm.

11. The method of claim 1 , wherein the tooling includes a bimodal distribution of sizes of the holes and/or recesses.

12. A method of fabricating cooling features on a CMC component, the method comprising:

vapor-depositing a matrix material onto a fabric preform to form a rigidized preform;

enclosing the rigidized preform in tooling without compaction of the rigidized preform, the tooling including holes and/or recesses facing the rigidized preform;

delivering gases through the holes and/or recesses to selectively deposit a the matrix material on the rigidized preform at locations adjacent to the holes, the tooling acting as a mask to prevent deposition of the matrix material on the rigidized preform away from the holes, and the matrix material being built up to form surface protrusions on the rigidized preform;

removing the tooling; and

densifying the rigidized preform, thereby forming a CMC component including raised surface features.

13. The method of claim 12 , wherein the rigidized preform comprises silicon carbide fibers and the matrix material comprises silicon carbide, and

wherein the CMC component includes a silicon carbide matrix reinforced with the silicon carbide fibers.

14. The method of claim 12 , wherein the gases include methyltrichlorosilane (CH 3 SiCl 3 ) and hydrogen gas (H 2 ).

15. The method of claim 12 , wherein the holes and/or recesses comprise tapered holes and/or recesses.

16. The method of claim 12 , wherein the raised surface features comprise pedestals or ribs.

17. The method of claim 16 , wherein each of the ribs has a length at least two times greater than a width thereof.

18. The method of claim 16 , wherein the ribs are curved.

19. The method of claim 12 , wherein a spacing between the raised surface features is at least about 0.06 cm.

20. The method of claim 12 , wherein the raised surface features have a height within a range from about 0.03 cm to about 0.10 cm.

21. The method of claim 12 , wherein the tooling includes a bimodal distribution of sizes of the holes and/or recesses.