Influence of laser scanning conditions on CFRP processing with a pulsed fiber laser

An experimental investigation of carbon fiber reinforced plastic (CFRP) composite processing with a high-power pulsed fiber laser was conducted. A CFRP plate was irradiated with laser light from a pulsed fiber laser with an average power of 125 W, a repetition rate of 167 kHz and a pulse width of 10 ns. The wavelength of the laser light was 1064 nm. A galvanometer scanner was used as the processing head for high-speed scanning of the pulsed laser light. A hatching distance was introduced, and the processing rates were measured according to the parameters of hatching distance and scanning speed. The walls at the grooves irradiated by laser light were observed using scanning electron microscopy (SEM) and cross-sectional profiles of the processed CFRP were measured using confocal laser scanning microscopy (CLSM). The kerf width was measured by optical microscopy observation of the CFRP sample surface processed by laser irradiation. The growth mechanism of the kerf and heat affected zone (HAZ) structures was investigated based on cross-sectional SEM micrographs of the kerfs. The optimal hatching distance for the target groove depth is discussed, together with the importance of the hatching distance for high-speed and high-quality processing of CFRP. The results indicate that adjustment of the hatching distance and the scanning speed are important for obtaining both good cutting speed and quality.