Ultra High Speed Laser Cutting of CFRP Using a Scanner Head

Laser cutting of CFRP is well known to be difficult because of the thermal damage to the CFRP material. Therefore, with the objectives of evaluating the cutting poss ibility for long- or short-fiber pellet CFRP sheets of 3 mm in thickness and obtaining narrower HAZ for better cut quality, ultra-high speed cutting was conducted by using a continuous-wave (cw) high-brightness disk laser with a scanner head. The increase in the laser power rendered the cutting time shorter and the kerf depth deeper for a CFRP full cut. It was revealed that CFRP cut with a narrow HAZ of less than 50μm could be produced under the conditions of laser powers of 2 to 5 kW, a cutting speed of 5 m/s, a time interval between repeated runs of 1 second and a defocused distance of 0 mm. It was also confirmed that short fiber pellet CFRP was more easily cut and suffered less thermal damage in comparison with a long fiber one. Furthermore, it was de monstrated that the tensile strength of fully laser-cut CFRP was almost equal to that of the base CFRP specimen. This means the laser-cut surfaces of the CFRP sheet were not degraded in mechanical properties.