Threshold properties of high modulus carbon fiber reinforced plastic composite with picosecond laser processing

Abstract

The picosecond laser processing thresholds and morphology characteristics of polyacrylonitrile-based high modulus carbon fiber reinforced cyanate ester composite (M55/BS-4) and an asphalt-based high thermal conductivity carbon fiber reinforced plastic (K600/5418) were studied. Diameter-regression method was used to test and compare the ablation threshold, threshold incubation effect, and single-pulse thresholds for each composite were predicted. The influence of incident energy fluence (0.7-25 J/cm2) and beam scanning velocity (0.2-5 m/s) on the incision quality was analyzed. The results show that the great difference in the fiber thermal conductivity leads to significant quantitative difference in processing threshold and morphology. Using the highest scanning speed (5 m/s) available and fluence equivalent to 3.2 times the single-pulse threshold (i.e., about 8 J/cm2), carbon fiber and resin can be almost synergically removed, characterized by uniform slit inlet widths and neat cutting edge. The use of higher scanning speeds coupled with appropriate processing energy is expected to further improve the quality of processing.