Tea CO₂ laser machining of carbon fiber-reinforced polymer composites

Carbon fibre-reinforced polymer (CFRP) composites have found wide applications in the aerospace and sport industries owing to their lightweight and acceptable mechanical properties compared to commonly used metallic materials. Machining of CFRP composites using lasers can be challenging due to in homogeneities in the material properties and structures, which can lead to thermal damages during laser processing. In previous studies, Nd:YAG, DPSS, continuous CO₂ and fibre lasers were used in cutting CFRP and the control damage such of heat affected zone (HAZ) remains a challenge. In this paper, an investigation into cutting and milling of CFRP composites using a pulsed TEA CO₂ laser is presented to understand the effect of the process parameters such as laser power, cutting speed and repetition rate on laser cutting quality. The examined quality characteristics include heat affected zone (HAZ) and taper angle. In addition, a surface protection technique using a sacrificial mask is used as a means to reduce thermal damage. Experimental results using this technique show good improvements in surface quality.