Thermal effect on CFRP ablation with a 100-W class pulse fiber laser using a PCF amplifier

An experimental study on CFRP processing is presented using a high-power pulsed fiber laser operated at a 1064-nm fundamental wavelength, a 100-W average power, a 1-MHz repetition rate, and a 10-ns pulse width under ambient air, a dry air jet, or a nitrogen gas jet. Raman spectroscopy and scanning electron microscopy are conducted to measure the heat-affected zone (HAZ) quantitatively. Here, the HAZ is defined as the sum of the matrix evaporation zone (MEZ) and the resin alteration zone (RAZ). The MEZ, RAZ, and HAZ in air exceed 600, 2550, and 3150 μm, respectively. In the case of N2 gas jet, the MEZ, RAZ, and HAZ are 30, 88, and 118 μm, respectively. The results show that a nitrogen gas jet most effectively suppresses the HAZ by suppressing oxidization of the carbon fiber and cooling of heat accumulation. Additionally, the cutting speed with a dry air jet or a nitrogen gas jet increases by about 10% compared to that in ambient air.