CMC Structures for Exhaust Nozzle Components Based on 3-D Woven Preforms

In Phase I of the proposed program we plan to demonstrate the feasibility of manufacturing bladetrack components using an approach that will result in substantial reductions in cost and cycle time compared with conventional 2-D lay-up methods. The approach involves use of a 3-D fiber preform with the shape of the final component, produced by an orthogonal weaving process developed at 3TEX, which is then infiltrated with a pressure infiltration method developed at TSC. The processing steps are amenable to a controlled manufacturing environment with minimal adjustment by hand labor. The use of 3-D woven preforms is also the most reliable method for ensuring adequate through-thickness properties, allowing process control during manufacture, and eliminating delamination as a failure mechanism during manufacture or during component service. It also eliminates the risk of processing defects due to incomplete bonding between layers or lay-up errors.