Laser cutting of CFRP using novel cutting strategies

Laser cutting of carbon fibre reinforced plastics generates a heat affected zone (HAZ) in the vicinity of the cut, affecting the integrity of the material and therefore the uptake of laser cutting for composite applications. This work uses mechanical testing to determine the effect of laser cutting on material properties and to see if they correlate with the observed HAZ. The potential for an extended-HAZ (exHAZ), where polymer remains but the properties have changed due to the proximity to the laser cut, is considered. This more novel concept of the exHAZ is important in understanding the performance of laser cutting CFRP and enabling wider use. A 2 kW multimode 1070 nm continuous wave fibre laser and a range of cutting strategies have been used to determine the influence of different cutting parameters on the HAZ. Cuts are generated using single and multi-pass (pseudo pulsed) cutting strategies with a range of assist gas pressures. The effect of assist gas has been largely overlooked in laser cutting of CFRP to date. The results obtained will provide guidance for future dynamic beam shaping work.