Minimization of chemical vapor infiltration tooling hole length through windows

A method of arranging a fibrous preform in a tooling assembly for chemical vapor infiltration (CVI), the method comprising:

• securing the fibrous preform within an inner tooling fixture, the inner tooling fixture formed from graphite and comprising:
• a plurality of inner sidewalls, each of the plurality of inner sidewalls having an inner wall thickness;
• and
• a plurality of holes extending through the inner wall thickness of at least one inner sidewall of the plurality of inner sidewalls;
• placing the inner tooling fixture within an internal volume of an outer tooling fixture, the outer tooling fixture formed from graphite and comprising:
• a plurality of outer sidewalls defining the inner volume, each of the plurality of outer sidewalls having an outer wall thickness;
• and
• a window extending through the outer wall thickness of at least one outer sidewall of the plurality of sidewalls;
• and
• wherein placing the inner tooling fixture within the internal volume of the outer tooling fixture comprising:
• orienting the inner tooling fixture such that the window overlaps with at least a subset of the plurality of holes, the subset of the plurality of holes comprising multiple of the plurality of holes;
• wherein the outer wall thickness and the inner wall thickness combine to define a length of a straight flow path through the window and one hole of the subset of holes;
• and
• wherein the one hole of the subset of holes has a diameter, and wherein the window has a width greater than the diameter, such that the flow path is wider at the window than at the one hole, and such that the window is simultaneously aligned with all of the subset of the plurality of holes.

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

• an outer tooling fixture formed from graphite and comprising:
• a plurality of outer sidewalls defining an inner volume, each of the plurality of outer sidewalls having an outer wall thickness;
• and
• a window extending through the outer wall thickness of at least one outer sidewall of the plurality of sidewalls;
• and
• an inner tooling fixture positioned within the inner volume of the outer tooling fixture, the inner tooling fixture formed from graphite and comprising:
• a plurality of inner sidewalls, each of the plurality of inner sidewalls having an inner wall thickness;
• and
• a plurality of holes extending through the inner wall thickness of at least one inner sidewall of the plurality of inner sidewalls;
• wherein the at least one outer sidewall is positioned adjacent the at least one inner sidewall such that the window entirely overlaps with each hole of the plurality of holes in the at least one inner sidewall;
• wherein the outer wall thickness and the inner wall thickness combine to define a length of a straight flow path through the window and one hole of the plurality of holes;
• and
• wherein the one hole of the plurality of holes has a diameter, and wherein the window has a width greater than the diameter, such that the flow path is wider at the window than at the one hole, and such that the window is simultaneously aligned with multiple of the plurality of holes.