A feasibility study on high-power fiber laser cutting of thick CFRP laminates using single-pass strategy

Abstract High-power fiber laser as an emerging technology has been developed for machining composite sheets (less than 5.0 mm thick) with relatively high efficiency, while very limited works are reported when using fiber laser to cut thick CFRP plates. In order to further explore the cutting capability of fiber laser system without sacrifice of efficiency, a feasibility study on high-power fiber laser cutting of thick CFRP laminates using single-pass strategy was carried out in this work. Surface morphology and cross-section characteristics were analyzed for further understanding laser-CFRP composite interaction/removal mechanisms. Various thermal defects were qualified to better understand the influence of processing parameters on machining quality. Results showed that relatively high level of laser power (4800 W) and cutting speed (2000 mm/min) were preferred to effectively improve surface quality and cut through samples during laser cutting process, while excessive laser energy damaged CFRP composites with severe cracks and delamination mainly due to high level of thermal stress. CFRP laminate with a thickness of 10.0 mm could be successfully cut through when using high-power fiber laser and single-pass strategy, the threshold of energy per unit length was about 270 J/mm. Experimental results from this work can provide significant benchmark data for further industrial applications.