Diode lasers enable rapid, strong repairs for combat aircraft

The use of a high-power diode laser to bond composite patches to aerospace materials was investigated with the goal of developing a method that will render combat aircraft airworthy again in the shortest possible time. In tests of the approach, samples were placed in a vacuum box. A high-power diode laser supplied 940-nm radiation in output powers ranging from 1.5 to 2.3 kW. The defocused, multimode beam illuminated the surface of the samples through the glass window of the vacuum box. The 6×4-mm beam was scanned across the 25-mm width of the APC-2 repair patch five times, overlapping itself by 1 mm on each pass. No melting of the surface of the patch was observed on any of the samples, either during or at the end of bonding. Preliminary results suggest that the high-power diode laser-based technique is a feasible solution to the potentially debilitating problem of grounded combat aircraft.