Ceramic matrix composite component having low density core and method of making

1. A ceramic matrix component comprising a fibrous core and a ceramic matrix composite shell surrounding at least a portion of the fibrous core, wherein the ceramic matrix composite shell comprises a fibrous preform and the fibrous core has a greater porosity than the fibrous preform and the fibrous core further comprises ceramic foam and the ceramic foam is positioned at a trailing edge of the fibrous core.

2. The ceramic matrix component of claim 1 , wherein a porosity of the fibrous core is 2-3 times greater than a porosity of the fibrous preform.

3. The ceramic matrix component of claim 1 , wherein the fibrous core comprises cooling passages.

4. The ceramic matrix component of claim 3 , wherein the cooling passages are located at a leading edge of the ceramic matrix component.

5. The ceramic matrix component of claim 3 , wherein the cooling passages are located at the trailing edge of the ceramic matrix component.

6. The ceramic matrix component of claim 1 , wherein the ceramic matrix composite shell has a thickness greater than or equal to 0.03 inch.

7. A method of making a ceramic matrix component comprising forming a fibrous core having a first porosity, forming a fibrous preform on the fibrous core wherein the fibrous preform has a porosity less than the first porosity, and forming a ceramic matrix on the fibrous preform using chemical vapor infiltration and the fibrous core further comprises ceramic foam and the ceramic foam is positioned at a trailing edge of the fibrous core.

8. The method of claim 7 , wherein the fibrous core comprises sacrificial fibers.

9. The method of claim 8 , wherein the sacrificial fibers are located at a leading edge of the fibrous core.

10. The method of claim 8 , wherein the sacrificial fibers are located at a trailing edge of the fibrous core.