Silicon carbide ceramic matrix composites
Ceramic matrix composite materials and processes for making said composite materials are disclosed.
1. A method of producing a silicon carbide (SiC) ceramic matrix composite (CMC), the method comprising:
forming a SiC fiber preform;
incorporating a slurry comprising yttrium or ytterbium into the SiC fiber perform via slurry infiltration; and
infiltrating the SiC fiber perform with a melt comprising silicon, therby forming the SiC ceramic matrix composite.
2. The method of claim 1 , wherein the slurry further comprises SiC.
3. The method of claim 1 , wherein the slurry comprises metallic yttrium, metallic ytterbium, yttrium oxide, ytterbium oxide, yttrium silicate and/or ytterbium silicate.
4. The method of claim 1 , wherein the slurry further comprises aluminum oxide.
5. The method of claim 1 , wherein the melt comprises a eutectic ally selected from a Y—Al—Si eutectic alloy and a Yb—Al—Si eutectic alloy.
6. The method of claim 1 , wherein the composite comprises a Y—Si—O compound and/or a Yb—Si—O compound.
7. The method of claim 6 , wherein the composite comprises yttrium silicide and/or ytterbium silicide selected from the group consisting of YSi, Y 5 Si 4 , Y 5 Si 5 , and YbSi.
8. The method of claim 1 , further comprising before the slurry infiltration, applying a fiber interface coating to the SiC fiber preform, the fiber interface coating comprising carbon, carbon nitride, boron nitride, silicon-doped boron nitride, silicon notride, or SiNC.
9. The method of claim 8 , further comprising, after applying the fiber interface coating, depositing a SiC matrix layer by chemical vapor infiltration.
10. The method of claim 9 , wherein the composite comprises:
the SiC fiber preform at 15-45 vol. % ;
the fiber interface coating at 1-10 vol. % ;
the SiC matrix layer at 10-30 vol. % ;
slurry additives at 10-30 and
melt infiltration additives at 5-20 vol. % .
11. The method of claim 1 , wherein the slurry includes from 3% to 100% by volume of yttrium silicate and/or ytterbium silicate and from 0 vol. % to 97 vol. % SiC.
12. The method of claim 1 , wherein the slurry comprises SiC, alumina, yttrium oxide and/or ytterbium oxide.
13. The method of claim 1 , wherein the slurry further comprises gadolinium oxide, erbium oxide, or lutetium oxide.