Mechanical Ignition of Al/Ni Reactive Multilayer Systems: Influence of Impacting Material, Its Properties, and Geometric Characteristics

Abstract

Al/Ni reactive multilayer systems (RMS) with a bilayer thickness of and total thickness μm on a SiO substrate exhibit a self‐propagating reaction after ignition. A common method to initiate the self‐propagating reaction is by electric spark ignition. Herein, RMS are ignited by a mechanical impact using various materials with indeterminate geometries to investigate the basic mechanisms. SiO2, glass, PMMA, and resin‐bonded SiC particles are used as impacting material with different geometrical impact areas. The used materials are placed on top of the RMS and a mechanical impulse is applied. The ignition behavior of the RMS is subsequently evaluated and classified. Additionally, the impacted RMS are examined by microscopy to reveal the damage pattern. By correlating particle size and spacing of the penetrating materials, an ignition threshold can be established. Moreover, the results demonstrate that the energy input threshold can be reduced through a strategic distribution of particles within the impacting and penetrating geometry. This provides valuable insights into the mechanical ignition fundamental and supports future applications of mechanical ignition of RMS.