Chemical vapor infiltration tooling for optimizing infiltration in ceramic matrix composites
A tooling fixture suitable for use in infiltrating a fibrous preform with a flow of reactant gas includes an outer surface and an inner surface defining a thickness therebetween, and a plurality of holes extending through the thickness of the tooling fixture. The plurality of holes includes a first hole having cylindrical geometry with a first pair of dimensions comprising a first length and a first diameter, a second hole having cylindrical geometry with a second pair of dimensions comprising a second length and a second diameter, and a third hole having cylindrical geometry with a third pair of dimensions comprising a third length and a third diameter. At least one dimension of the first pair of dimensions is different from at least one dimension of the second pair of dimensions, and at least one dimension of the second pair of dimensions is different from at least one dimension of the third pair of dimensions.
1 . A tooling fixture suitable for use in infiltrating a fibrous preform with a flow of reactant gas, the tooling fixture comprising:
an outer surface and an inner surface defining a thickness therebetween, the inner surface configured to be disposed adjacent to the fibrous preform; and
a plurality of holes extending through the thickness of the tooling fixture, the plurality of holes comprising:
a first hole having cylindrical geometry about a first axis with a first pair of dimensions comprising a first length and a first diameter, wherein the first diameter, measured orthogonal to the first axis, is uniform throughout the first hole;
a second hole having cylindrical geometry about a second axis with a second pair of dimensions comprising a second length and a second diameter, wherein the second diameter, measured orthogonal to the second axis, is uniform throughout the second hole, the second diameter less than the first diameter; and
a third hole having cylindrical geometry about a third axis with a third pair of dimensions comprising a third length and a third diameter, wherein the third diameter, measured orthogonal to the third axis, is uniform throughout the third hole; and
wherein the first hole is located to be disposed proximate a first location of the preform and wherein the second hole is located to be disposed proximate a second location of the preform, wherein the first location of the preform is thicker than the second location of the preform.
2 . The tooling fixture of claim 1 , wherein the first length is different from the second length.
3 . The tooling fixture of claim 1 , wherein the second diameter is different from the third diameter.
4 . The tooling fixture of claim 1 and further comprising:
a fourth hole having cylindrical geometry with a fourth pair of dimensions comprising a fourth length and a fourth diameter; and
a fifth hole having cylindrical geometry with a fifth pair of dimensions comprising a fifth length and a fifth diameter;
wherein at least one dimension of the fourth pair of dimensions is different from at least one dimension of the fifth pair of dimensions; and
wherein at least one dimension of the fifth pair of dimensions is different from at least one dimension of the first, second, or third dimensions.
5 . The tooling fixture of claim 4 , wherein the fourth diameter is different from the fifth diameter, and wherein the fourth length is different from the fifth length.
6 . The tooling fixture of claim 1 and further comprising:
a plurality of first holes;
a plurality of second holes; and
a plurality of third holes.
7 . The tooling fixture of claim 1 , wherein the tooling fixture is formed from at least one of graphite, a refractory metal alloy, a carbon-carbon composite, and a ceramic material.
8 . The tooling fixture of claim 1 , wherein each hole of the plurality of holes is disposed to direct the flow of reactant gas to a surface of the fibrous preform.
9 . The tooling fixture of claim 8 , wherein the fibrous preform is formed from silicon carbide.
10 . The tooling fixture of claim 9 , wherein the fibrous preform is shaped like an airfoil.
11 . The tooling fixture of claim 1 , wherein at least one hole of the plurality of holes is oriented at an oblique angle with respect to the outer surface of the tooling fixture.
12 . The tooling fixture of claim 8 , wherein at least one hole the plurality of holes is oriented normal to the outer surface of the tooling fixture.
13 . The tooling fixture of claim 1 , wherein the tooling fixture has a first thickness at a location of the first hole and has a second thickness at a location of the second hole, wherein the first thickness is greater than the second thickness.
14 . The tooling fixture of claim 13 , wherein the first hole is disposed through a corner region defined on the outer surface of the tooling fixture.
15 . The tooling fixture of claim 1 , wherein the thickness of the tooling fixture is uniform.
16 . The tooling fixture of claim 1 , wherein the inner surface of the tooling fixture has a curved shape and wherein the first hole opens to a region on the inner surface of greater curvature and the second hole opens to a region on the inner surface of reduced curvature.