Initiation of a reaction in aluminum-Teflon multilayer thin-film samples by drop-hammer impact loading

Experimental results on the initiation of samples composed of alternating layers of aluminum foil (0.65, 4, 10, or 20 μm in thickness) and Teflon films (20 or 50 μm) by drop-hammer impact loading are presented. In contrast to powdery mixtures, lamellar compositions have a rigorously controlled surface area of contact of the interacting components. The light flash signifying the event of initiation and the impact pressure were recorded with a photodiode and a tensiometer, respectively. It was established that, under typical condition of initiation of HEs, the aluminum-Teflon lamellar samples are deformed as brittle materials. At a certain pressure, after the stage of elastic compression, a rapid disintegration (within 30 μs) with the formation of local reaction initiation sites at shear surfaces of individual segments occurs. The results obtained are indicative of the mechanochemical nature of the interaction between aluminum and Teflon layers under impact loading conditions.