Room-Temperature Filler for Honeycomb Repairs

Improvements are needed in composite repair materials used on U.S. Navy aircraft.  The current materials used for repair of honeycomb sandwich composites require excessive cure times which delays aircraft availability. TRI-Austin proposes development of a new syntactic foam that provides rapid cure at room temperature with low cure exotherm. The formulation work will include an investigation of bimodal distributions of glass microballoons and incorporation of low loadings of high aspect ratio reinforcing fillers. Phase I feasibility will be shown by demonstrating a new lightweight, efficiently processed composite honeycomb repair material with demonstrable reductions in ambient cure time and improved mechanical property performance. A concurrent objective will also be pursued to increase the thermal conductivity of the syntactic foam to regulate the heat generated during cure exotherm. Cure kinetics will be determined analytically and with simulated repairs. Resin cost analysis and estimates for continued raw material availability will also be established. TRI/Austin brings experience in the field of syntactic foam development and composite repair. The development team also includes a company that specializes in composite repair technology and training.