Performance evaluation of fiber-based ballistic composites against laser threats

The interaction between a laser and a composite material has been an intense subject within the past decade and become an emerging field for the defense and manufacturing industry since high-power lasers were initiated to be utilized for the directed-beam applications. In this study, a specially developed composite material for the ballistic applications was shined to a continuous wave (CW) laser beam at 915 nm. The ballistic material was composed of 77 layers of the single sheet of the SR-3136 by Spectra Shield® from Honeywell consisting of ultra-high molecular weight polyethylene (UHMW-PE) fibers reinforced with low-density PE (LD-PE) fibers and a polyurethane-based thermoplastic resin. At the instant of the exposure, the region of interest was completely evaporated and punctured with a slight swelling around the hole where the temperature was over 450 °C. The composite material was drilled completely upon exceeding 20 kJ of laser energy. The chemical and physical changes on the composite material after the laser exposure were extensively studied by a combination of techniques including High-Resolution Scanning Electron Microscopy (HR-SEM), Energy Dispersive X-ray Spectroscopy (EDX) and X-ray Photoelectron Spectroscopy (XPS). The physical properties of a single layer of the SR-3136 were also studied using HR-SEM, UV-VIS-NIR Absorption Spectroscopy, Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC) and XPS. The research presented here reveals the first study on the effects of the high-power laser beam irradiance on the fiber-reinforced composite materials utilized for the ballistic protection.