Hypersonic impact flash characteristics of a long-rod projectile collision with a thin plate target

Abstract Impact flash occurs when objects collide at supersonic speeds and can be used for real-time damage assessment when weapons rely on kinetic energy to destroy targets. However, the mechanism of impact flash remains unclear. A series of impact flash experiments of flat-head long-rod projectiles impacting thin target plates were performed with a two-stage light gas gun. The impact flash spectra for 6061 aluminum at 1.3–3.2 km/s collision speeds were recorded with a high-speed camera, a photoelectric sensor, and a time-resolved spectrometer. The intensity of the impact flash exhibited a pulse characteristic with time. The intensity (I) increased with impact velocity (V0) according to I ∝ V 0 n , where n = 4.41 for V0 > 2 km/s. However, for V0   2 km/s, a continuous spectrum (thermal radiation background) was observed and increased in intensity with V0. However, for V0