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.

Experimental investigation of high-power laser irradiation of missile materials in subsonic and supersonic flows

“…This becomes apparent by revealed carbon fibers and the decomposed epoxy matrix. Due to their thermal stability, the carbon fibers were mostly unaffected in their structure, while the epoxy resin was decomposed, as known from previous studies [12]. In addition, CFRP layers were ablated incrementally resulting in a sharply confined and conically shaped penetration channel.…”

“…The second part of the investigations focused on laser-matter interaction. The material and parameter selection were oriented on previous experimental studies carried out at Fraunhofer EMI including laser irradiations with laser powers up to 10 kW [12] [13]. Furthermore, the selected test materials as well as the generic geometries of the models were also considered to be representative for corresponding missile threat scenarios.…”

Change of dominant material properties in laserperforation process with high-energy lasers up to 120kilowatt

“…Because large spot sizes require much higher laser powers, while maintaining similar intensities to those typically used for small spot sizes, large spot size applications could not be developed until the advent of such powerful lasers. As a result, there are only a few reports on applications using large spot sizes in the centimetre range [8][9][10][11][12][13][14][15][16][17][18][19][20] .…”

Investigation of the polymer material perforation time: comparison between two fiber laser wavelengths

“…The experimental setup is depicted in Figure 1 and is inspired from a similar experiment of perforation time on polymer material [5]. It consists in a collimated commercial fiber laser launched onto a sample.…”

“…The lasers had a wavelength of 1070 nm and 1943 nm and are referred as 1 µm and 2 µm wavelengths. The wavelengths were chosen according to previous experiments performed on polymer material [5], [6]. Both lasers had a beam quality M 2 < 1.1.…”