Experimental study on 800 nm femtosecond laser cutting of polyamide in air

The polyamide (PA) bars were cut by 1064 nm nanosecond pulsed laser and 800 nm femosecond pulsed laser respectively. By comparing the experimental results, it was found that the nanosecond pulse laser has a significant thermal effect on the cutting of PA, obvious ablation defects were observed and the ablation process of PA was mainly governed by photothermal effect. Femtosecond pulsed laser with its ultrashort pulse duration and high power density, achieved relatively good processing effect of PA and photochemical effect was thought to be dominant. In order to further improve the processing quality by reducing the heat accumulation of femtosecond laser pulses. The femtosecond laser processing was divided into 3 types according to the motion modes of the PA bar, including translation, rotation as well as translation and rotation. The cutting effects were compared, the optimal surface roughness of the cutting surface could reach 5 mu m and no obvious thermal features were observed. This study presented a feasible technological method for polymer processing using femtosecond laser.