Influence of laser process on mechanical behavior during cutting of carbon fiber reinforced plastic composites

Carbon fiber-reinforced plastics (CFRP) composite is most attractive materials to reduce the weight of transportations. To increase the production volume and the efficiency in the field of CFRP component, fast, highly precise and cost-efficient technologies are required. Although laser cutting meets these requirements, it is not used because of insufficient knowledge about the effect of thermal damage on the material behavior. In this study, the effect of several cutting processes on the static tensile strength and the fatigue strength was evaluated for CFRP consisting of thermoset resin matrix and carbon fibers. The CFRP was cut using two different-type of lasers; a CO₂ gas laser and single-mode fiber lasers, and a conventional mechanical tool. The mechanical cutting specimen produced a cut of high quality. While, the laser cutting specimens clearly showed a heat-affected zone (HAZ). The static tensile strength and the fatigue strength by laser cutting specimens clearly decreased in comparison with mechanical cutting specimen. The laser cutting specimen exhibited a linear dependency of the tensile strength on the HAZ, indicating that the main effect resulted from thermal destruction of CFRP within the HAZ.