Investigation of Film Reinforced Composites for Aircraft Structures

摘要

The main objective of the program was to develop improved mechanical properties of boron thin-film reinforcement. Optical examinations of laminates made by bonding together multiple layers of vacuum evaporated boron supported on polyimide substrates in earlier programs had shown significant variations in glue-line thickness and reinforcement planarity. The present program emphasized methods of reducing these types of laminate imperfections. Three approaches were experimentally tested. The best results were obtained with laminates made with polyimide film (Kapton), 1/4 mil thick, as the substrate. This was vacuum coated on both sides with boron using a screen carrier in the vacuum coating operation. Multiple layers were bonded together to make laminates for mechanical testing. The optimum mechanical properties obtained are given. (Author)