Carbon cloth damage induced by various shapes of CO2 laser pulses

Abstract

A qualitative study of the damages on a carbon cloth induced by various shapes of CO2 laser pulses is presented. Three pulse shapes were used: short (100 ns, 84 MW/cm(2)), tailed (similar to 100-ns spike of 70 MW/cm(2), 2-mu s tail), and extralong (45 mu s, 0.5 MW/cm(2)). Apparently, the energy absorbed by the cloth was mainly converted into thermal energy, causing a range of damages, from instantaneous evaporation to cracking and melting, all of which resulted in the cutting of individual fibers in the yarns of the cloth. The two longer types of pulses allowed sufficient time for the stabilization of the affected zone temperature, thus producing melting and a crater-like burning through of the cloth.