Minimization of chemical vapor infiltration tooling hole length through counterbores

1 . A tooling assembly suitable for use in infiltrating a fibrous preform, the tooling assembly comprising:

a perforated fixture having a thickness defined between a first side and an opposite second side of a monolithic body, the fixture comprising:

a plurality of holes extending through the thickness; and

a first counterbore extending partially through the thickness to define a first region in which the thickness is reduced;

wherein a subset of the plurality of holes extends through the first region, the subset comprising at least three holes; and

wherein the thickness in the first region is non-uniform, and wherein a first hole of the subset has a first length, and wherein a second hole of the subset has a second length different from the first length.

2 . The tooling assembly of claim 1 , wherein the perforated fixture is formed from at least one of graphite, a refractory metal alloy, a non-graphitic carbon material, and a ceramic material.

3 . The tooling assembly of claim 1 and further comprising: a second counterbore extending partially through the thickness to define a second region in which the thickness is reduced.

4 . The tooling assembly of claim 3 , wherein the second counterbore has a circular geometry with a first diameter.

5 . The tooling assembly of claim 4 , wherein at least one hole of the plurality of holes extends through the second region and has a second diameter smaller than the first diameter.

6 . The tooling assembly of claim 3 , wherein the second counterbore has a circular geometry and the first counterbore has a rectangular geometry.

7 . The tooling assembly of claim 3 , wherein the thickness in the second region is less than the thickness in the first region.

8 . The tooling assembly of claim 1 , wherein the first counterbore has a rectangular geometry.

9 . The tooling assembly of claim 1 , wherein the perforated fixture is configured to interface with a fibrous preform.

10 . The tooling assembly of claim 9 , wherein the first counterbore and the subset of plurality of holes is configured to align with the fibrous preform.

11 . The tooling assembly of claim 9 , wherein the fibrous preform is formed from silicon carbide.

12 . The tooling assembly of claim 1 , wherein a subset of the plurality of holes extends through a second region in which the thickness is unreduced by a counterbore.

13 . A tooling assembly suitable for use in infiltrating a fibrous preform, the tooling assembly comprising:

a perforated fixture having a thickness defined between a first side and an opposite second side of a monolithic body, the fixture comprising:

a plurality of holes extending through the thickness;

a first counterbore extending partially through the thickness to define a first region in which the thickness is reduced; and

a second counterbore extending partially through the thickness to define a second region in which the thickness is reduced;

wherein at least one of the plurality of holes extends through the first region and a subset of the plurality of holes extends through the second region, the subset comprising at least three holes; and

wherein the thickness in the second region is non-uniform, and wherein a first hole of the subset has a first length, and wherein a second hole of the subset has a second length different from the first length.

14 . The tooling assembly of claim 13 , wherein the first counterbore has a circular geometry, and wherein the second counterbore has a rectangular geometry.

15 . The tooling assembly of claim 13 , wherein the perforated fixture is formed from at least one of graphite, a metallic material, a non-graphitic carbon material, and a ceramic material.

16 . The tooling assembly of claim 13 , wherein the thickness in the second region is less than the thickness in the first region.