Study on the CFRP nanosecond laser cutting damage and efficiency by aspiration system assisted method

In the present work, the aspiration system assisted method is investigated on low-damage and high-efficiency carbon fiber reinforced polymer (CFRP) nanosecond laser cutting. Experiments parameters with three aspiration system assisted conditions (no aspiration system assisted, unilateral aspiration system assisted, bilateral aspiration system assisted), different frequencies, and overlap rates are designed. The analysis focuses on the cutting time of through-cut, heat affect zone (HAZ) on the entrance surface, roughness, and microdefect on sidewall of cutting holes. The results indicate aspiration system assisted can reduce the HAZ of laser cutting hole, the sidewall roughness, and cutting time. The cutting time with bilateral aspiration system assisted is shortest, with a maximum reduction of 24.8 % compared to no aspiration system assisted at a frequency of 100 kHz and an overlap rate of 85 %. Aspiration system assisted reduces the HAZ, and its placement has an effect on cutting hole quality, proximal HAZ 11.11 & mu;m is greater than distal HAZ 6.96 & mu;m with unilateral aspiration system assisted. All sidewalls of cutting holes have a ladder-like interface, and an interface height difference up to 43 & mu;m. It appears in the intermediate position of CFRP plate or exit of cutting holes. With no aspiration system assisted, large voids appear below a ladder-like boundary surface, and the maximum value of voids reaches 290 & mu;m. Aspiration system assisted remove the carbon fiber debris and the plasma plume generated by laser cutting, avoiding accumulation and combustion in the slit, reducing the absorption of laser energy by carbon fiber debris and plasma plume, effectively improving cutting quality and efficiency.