High-energy laser effects on carbon fiber reinforced polymer composites with a focus on perforation time

Abstract

Commercially available carbon fiber reinforced polymer matrix composite panels (Hexply® M18-1/G939 and 8552/IM7) with different thicknesses (1-6 mm) were exposed to continuous-wave high-energy laser radiation at various laser powers up to 10 kW under static conditions. The perforation times, the size of the damaged volume and the residual compressive strengths are determined and correlated to the irradiation parameters. It is found that for the time of perforation, the damaged volume, which is approximated by a cylinder shaped model, correlates linearly with the laser energy imposed onto the sample surface. This relationship can be used for a prediction of the perforation time for various laser powers, material thicknesses and laser spot diameters. Increasing laser energy results in a decay of residual compressive strength after impact. Visual inspection as well as micro-focused computed X-ray tomography and scanning electron microscopy indicate a small area of thermal damage outside the laser spot. Additionally, infrared spectroscopy characterizes incipient heat damage most sensitively.