Waterjet Techniques for Composite Material Jet Engine Component Repair. Phase 1

摘要

This Phase 1 SBIR project addressed the feasibility of using abrasive-waterjet(AWJ) machining technology for the repair of jet engine components fabricated from composites. AWJ milling techniques were adapted to remove precise amounts of the composite materials without damage such as delamination or fiber pullout. The approach can be used for the removal of damaged sections of composite components and high-precision preparation of the affected area before bonding or fastening of patching material. Machining of two common composite repair geometries was demonstrated, including low-angle straight-scarf joints and stepped-lap joints. For the former case, the objective was to produce two 6-degree walls with a flat-bottomed pocket between them. In the latter, the objective was to machine a series of steps with heights equal to the ply thickness, typically 0.007-0.008 inch. Demonstration straight-scarf parts were produced in two materials with the desired pocket lengths and depths and wall angles of 5.0 to 6.0 degrees. Stepped-lap parts were also produced in the two materials with step heights deviating from the ply thickness by no more than 0.001 inch. The demonstrated ability to predict and control the material removal pattern indicates that this technique can find wide application in precision shaping of aerospace composites.