A mandrel for a molding process. The mandrel includes a first portion that has a first draft surface and a second draft surface. A second portion and a third portion are included. The second portion has a third draft surface and the third portion has a fourth draft surface wherein the first draft surface engages the third draft surface and the second draft surface engages the fourth draft surface. A channel extends along a length of the mandrel at an interface between the first, second, and third portions such that the second portion does not contact the third portion.

A mandrel for a molding process. The mandrel includes a first portion that has a first draft surface and a second draft surface. A second portion and a third portion are included. The second portion has a third draft surface and the third portion has a fourth draft surface wherein the first draft surface engages the third draft surface and the second draft surface engages the fourth draft surface. A channel extends along a length of the mandrel at an interface between the first, second, and third portions such that the second portion does not contact the third portion.

A method for molding a ceramic core includes introducing a slurry to a mold and vibrating the mold. The slurry has: silica-containing particles; polymer fiber; and matrix precursor. The mold has an outer tool and a liner held within the outer tool. The vibrating comprises operating a plurality of vibration transducers distributed along the mold.

A method for molding a ceramic core includes introducing a slurry to a mold and vibrating the mold. The slurry has: silica-containing particles; polymer fiber; and matrix precursor. The mold has an outer tool and a liner held within the outer tool. The vibrating comprises operating a plurality of vibration transducers distributed along the mold.

A method of fabricating an airfoil includes providing an airfoil core tube that is made of a rigidized ceramic fabric, using the airfoil core tube as a mandrel by braiding a plurality of ceramic fiber tows around the airfoil core tube to form one or more braided layers, where the airfoil core tube and the one or more braided layers forming an airfoil preform, and densifying the airfoil preform with a ceramic matrix material to thereby form a ceramic matrix composite airfoil.

A method of fabricating an airfoil includes providing an airfoil core tube that is made of a rigidized ceramic fabric, using the airfoil core tube as a mandrel by braiding a plurality of ceramic fiber tows around the airfoil core tube to form one or more braided layers, where the airfoil core tube and the one or more braided layers forming an airfoil preform, and densifying the airfoil preform with a ceramic matrix material to thereby form a ceramic matrix composite airfoil.

A method of fabricating an airfoil includes providing an airfoil core tube that is made of a rigidized ceramic fabric, using the airfoil core tube as a mandrel by braiding a plurality of ceramic fiber tows around the airfoil core tube to form one or more braided layers, where the airfoil core tube and the one or more braided layers forming an airfoil preform, and densifying the airfoil preform with a ceramic matrix material to thereby form a ceramic matrix composite airfoil.

A method of fabricating an airfoil includes providing an airfoil core tube that is made of a rigidized ceramic fabric, using the airfoil core tube as a mandrel by braiding a plurality of ceramic fiber tows around the airfoil core tube to form one or more braided layers, where the airfoil core tube and the one or more braided layers forming an airfoil preform, and densifying the airfoil preform with a ceramic matrix material to thereby form a ceramic matrix composite airfoil.