Ceramic matrix composite surfaces with open features for improved bonding to coatings

摘要

A method to form an improved hybrid ceramic matrix composite structure comprises providing a ceramic matrix composite (CMC) with open features at a surface and applying a thermal barrier coating to the surface. The thermal barrier coating is preferably a friable graded insulation coating (FGI) having hollow ceramic spheres. For acceptance of a FGI coating the open features have a center-to-center separation distance in one or more directions that is between about 100 and about 1,000 percent of the diameter of the hollow ceramic spheres in the FGI and a depth that is between about 20 percent and about 200 percent of the diameter of the hollow ceramic spheres in the FGI. The open feature can result from the winding of tows about a mandrel; the lay-up of fabric including a surface fabric having an open weave; or the use of a 3-D weave, or a 3-D braid.