Abstract
Carbon fiber reinforced plastic (CFRP) is a key material for lightweighting in aerospace, automotive and other fields. It has the characteristics of anisotropy, high strength, and high hardness. In the processing of CFRP, the use of traditional machining has disadvantages such as severe tool wear, obvious delamination, micro-cracks, and changes in material properties during processing. Laser processing for CFRP provides a non-contact and wear-free processing method. However, it will cause the epoxy resin to generate the heat load, leading to the heat affected zone (HAZ) during the processing. The HAZ is the important indicator of the cutting quality and directly affects the material mechanical properties. Femtosecond pulsed laser with its "cold processing" advantage can greatly reduce the laser's thermal damage to materials and reduce the material's HAZ. In this paper, the cutting process of CFRP by ultraviolet femtosecond pulsed laser is studied. A UV femtosecond laser with a maximum average power of 15W was used to conduct cutting experiments on 2mm thick CFRP. Using the experimental method of single factor analysis, the effect of laser average power, repetition frequency, scanning speed, scanning times, scanning track spacing on cutting quality was studied. The results show that when the average power is 13W, the repetition frequency is 500khz, the scanning speed is 9m/s and other appropriate process parameters, the width of the HAZ is about 25um.