Investigation on mechanism for water-gas jet-assisted laser processing of carbon fiber-reinforced polymer

Water-jet-assisted laser processing suffers from energy losses, while gas-assisted laser processing encounters insufficient cooling. To better address these issues, this paper proposes a method of water-gas jet-assisted laser processing for carbon fiber-reinforced polymer (CFRP) materials to explore the thermal damage control effect in laser processing of CFRP. The method of water-air jet-assisted laser processing involves the formation of a water layer by the impact of a water jet on the workpiece, followed by the addition of auxiliary gas above the water layer to impact it. This method effectively suppresses water splashing and debris interference, thus enhancing the quality of CFRP processing. The present research investigates the effects of air pressure, water pressure, gas jet-target distance, and gas nozzle diameter on CFRP processing quality through single-factor experiments, which are subsequently optimized using orthogonal experiments. Furthermore, a three-dimensional model for water-gas jet-assisted laser processing was established in this study, and the flow field was analyzed using computational fluid dynamics software, aiming to explore methods for optimizing the flow field. Experimental and simulation results demonstrate that the water-air jet-assisted laser processing technique ensures both the cooling effect of water and minimizes the impact of the water layer on the laser transmission path, thereby facilitating the achievement of thermal balance removal in CFRP.