Wavelength and Pulsewidth Dependences of Laser Processing of CFRP

Abstract

As the use of CFRP material becomes widespread in various industries, achieving high-speed cutting with less pulse energy and minimal thermal damage is one of the important issues for laser-based processing. Among the various parameters in laser processing, we have focused on wavelength from UV (266 nm) to NIR (1064 nm) and pulsewidths from 100 fs to 20 ns in order to investigate cutting efficiency in terms of ablated mass per irradiated laser energy and corresponding heat affected zone (HAZ). Samples used in our experiments were uni-directional CFRPs with thickness from 140 μm to 250 μm or 1.3 mm-thick cross CFRPs. We measured time to cut the samples and ablated volume in order to estimate cutting efficiency in mg/kJ. Also we observed SEM images of the processed samples to evaluate HAZ. In general, shorter wavelength and shorter pulsewidth resulted in higher cutting efficiency and less thermal damages. These results could contribute to optimize the machining of CFRP composite materials.