Machinable CMC insert

1. An assembly for use in a gas turbine engine, the assembly comprising

a ceramic matrix composite component having an exterior surface,

a monolithic insert bonded to the exterior surface of the ceramic matrix composite component, and

a polymer char sandwiched between the monolithic insert and the exterior surface of the ceramic matrix composite component that bonds the monolithic insert to the ceramic matrix composite component, wherein the ceramic matrix composite component and the monolithic insert are co-infiltrated with silicon, silicon alloy, silicon carbide, or a combination thereof.

2. The assembly of claim 1 , wherein the monolithic insert comprises a resin char comprising silicon containing ceramic material, chopped carbon fibers, chopped silicon carbide fibers, or a combination thereof.

3. The assembly of claim 1 , wherein the monolithic insert comprises a pressed powder comprising silicon carbide powder and a binding agent.

4. The assembly of claim 1 , wherein the monolithic insert comprises a ceramic material comprising silicon carbide.

5. The assembly of claim 1 , wherein the monolithic insert comprises a reticulated foam having a continuous porosity.

6. The assembly of claim 1 , wherein the ceramic matrix composite component comprises a blade track, a vane, a blade, a combustor tile, an exhaust tail cone, or a combination thereof.

7. The assembly of claim 1 , wherein the ceramic matrix composite component comprises a recess along the exterior surface for mating with the monolithic insert.

8. The assembly of claim 7 , wherein the ceramic matrix composite component comprises a blade track segment with the recess along the exterior surface.

9. The assembly of claim 8 , wherein the monolithic insert comprises a dovetail post arranged to mate with the recess of the blade track segment.

10. The assembly of claim 8 , wherein the monolithic insert comprises a positioning tab for mating with the recess of the blade track segment.

11. The assembly of claim 1 , further comprising a ply of fabric wrapped over at least a portion of the monolithic insert and the ceramic matrix composite.

12. The assembly of claim 11 , wherein the ply of fabric comprises silicon-carbide fibers.

13. A method of joining a monolithic insert to a ceramic matrix composite component for use in a gas turbine engine, the method comprising

providing a ceramic preform comprising silicon carbide fibers,

depositing a pre-ceramic polymer along an exterior surface of the ceramic preform,

positioning the monolithic insert along the exterior surface of the ceramic preform such that the pre-ceramic polymer is sandwiched between the ceramic preform and the monolithic insert,

heating the pre-ceramic polymer to form a polymer char that bonds the monolithic insert to the ceramic preform, and

co-infiltrating the ceramic preform and the monolithic insert with liquid silicon, silicon alloy, silicon carbide, or a combination thereof.

14. The method of claim 13 , wherein co-infiltrating comprises chemical vapor infiltration, chemical vapor deposition, slurry infiltration, melt infiltration, polymer impregnation and pyrolysis, or a combination thereof.

15. The method of claim 14 , wherein the pre-ceramic polymer comprises a ceramic phase, SiC, a transition metal, a transition metal boride, a transition metal silicide, or combinations thereof.

16. The method of claim 13 , wherein heating the pre-ceramic polymer is performed at a temperature between about 1300° C. and about 1500° C.

17. The method of claim 13 , further comprising placing a ply of fabric to cover at least a portion of the monolithic insert and the ceramic preform.

18. The method of claim 13 , further comprising machining the monolithic insert after bonding the monolithic insert to the ceramic preform.

19. The method of claim 13 , wherein heating the pre-ceramic polymer to form the polymer char is performed contemporaneously with at least some portion of co-infiltrating the ceramic preform and the monolithic insert.