Article with cooling holes and method of forming the same
A method of making an ceramic article according to an exemplary embodiment of this disclosure, among other possible things includes arranging fiber plies into a preform, inserting one or more sacrificial springs to the preform, infiltrating the preform with a matrix material to form an article, and thermally degrading the one or more sacrificial springs to form cooling holes. A ceramic article and a gas turbine engine component are also disclosed.
1 . A gas turbine engine component, comprising:
a plurality of fibers arranged in generally planar fiber plies, there being a plurality of the fiber plies placed on top of each other;
a ceramic matrix material surrounding the fiber plies; and
helical cooling holes extending through the component, wherein the fibers in the fiber plies surround the helical cooling holes and are continuous local to the helical cooling holes;
wherein the helical cooling holes each extend along a spiral generally centered on an axis, the axis being perpendicular to a plane of the fiber plies, and the fibers being ceramic fibers;
wherein the component is a liner for use in a gas turbine engine combustor; and
wherein there are at least two segments of said plurality of fibers each including one or more helical cooling holes extending through the segments, with fibers in the fiber plies forming each of the segments surrounding the one or more cooling holes of the respective segments; and
wherein there is a gap between the at least two segments with no fiber plies, and said at least two segments are formed in a single liner for use in a gas turbine engine combustor.
2 . The gas turbine engine component of claim 1 , wherein ceramic spheres are positioned in the gap to maintain the gap.
3 . The gas turbine engine component of claim 2 , wherein the spheres are formed of Si 3 N 4 or SiC.