UV laser high-quality drilling of CFRP plate with a new interlaced scanning mode

Abstract Based on the default sequential scanning mode (SSM) of the top-down multi-layer concentric circle filling scanning process, an interlaced scanning mode (ISM) is proposed to improve the surface quality of the carbon fibre reinforced polymers (CFRP) plate by a nanosecond UV laser drilling. The mechanism of the CFRP laser drilling has been described. Several experiments are conducted to explore and compare the surface quality under these two different scanning modes. Compared with SSM, the overall average HAZ width of ISMs is reduced by 25.85% by reducing the heat accumulation effect of adjacent trajectories. The best parameter combination for ISM reduces the HAZ width (39.81 µm to 17.91 µm) and taper (0.138 to 0.067) of hole by 55.01% and 51.48% respectively compared to the default SSM. The damage degree of the HAZ and its vicinity using ISM is less than that using SSM, and the micro surface defects are also less.