Internal tooling configuration for the creation of z-channels in woven ceramic matrix composite preforms
A tooling assembly for use in forming z-channels in a fibrous ceramic preform includes a mandrel having a first plurality of holes extending into a mandrel body, a first subset of the plurality of holes being through-holes extending completely through the mandrel, and a second subset of the holes comprising blind pockets, and a plurality of channels extending longitudinally along the mandrel in a direction orthogonal to the first plurality of holes. The tooling assembly further includes an outer fixture at least partially enclosing the mandrel, the outer fixture including at least one piece comprising a second plurality of holes extending completely through the at least one piece, the second plurality of holes being aligned with respective corresponding ones of the first plurality of holes such that a needle can be inserted through each of the second plurality of holes in the at least one piece and into the respective ones of the first plurality of holes in the mandrel.
1 . A tooling assembly for use in forming z-channels in a fibrous ceramic preform, the tooling assembly comprising:
a mandrel having:
a first plurality of holes extending into a mandrel body, a first subset of the plurality of holes being through-holes extending completely through the mandrel, and a second subset of the holes comprising blind pockets; and
a plurality of channels extending longitudinally along the mandrel in a direction orthogonal to the first plurality of holes; and
an outer fixture at least partially enclosing the mandrel, the outer fixture comprising:
at least one piece comprising a second plurality of holes extending completely through the at least one piece, the second plurality of holes being aligned with respective corresponding ones of the first plurality of holes such that a needle can be inserted through each of the second plurality of holes in the at least one piece and into the respective ones of the first plurality of holes in the mandrel.
2 . The tooling assembly of claim 1 , wherein the at least one piece of the outer fixture comprises a first piece removably securable to a second piece.
3 . The tooling assembly of claim 1 , wherein the outer fixture is formed from one of plastic, metal, and graphite.
4 . The tooling assembly of claim 1 , wherein the mandrel is a multipiece mandrel comprising a first mandrel piece and a second mandrel piece.
5 . The tooling assembly of claim 1 , wherein the mandrel is formed form graphite.
6 . The tooling assembly of claim 1 , wherein each of the first plurality of holes has a first diameter.
7 . The tooling assembly of claim 6 , wherein each of the second plurality of holes has a second diameter.
8 . The tooling assembly of claim 7 , wherein the first diameter is the same as the second diameter.
9 . The tooling assembly of claim 7 , wherein the first diameter is greater than the second diameter.
10 . The tooling assembly of claim 1 , wherein at least a subset of the first plurality of holes is oriented such that a needle can be inserted within 10 degrees of normal to an outer surface of preform supported by the mandrel.
11 . The tooling assembly of claim 1 , wherein at least a subset of the first plurality of holes is oriented such that a needle can be inserted within 15 degrees of normal to an outer surface of preform supported by the mandrel.