Laser-induced ablation of fibre/epoxy composites

Abstract

Steady-state ablation rates and surface temperatures induced by a continuous wave CO2 laser were measured for three composites in environments of flowing air or argon. The composites were glass/epoxy, Kevlar/epoxy and carbon/epoxy. Irradiances ranged from 27 to 270 MW m -2. From these measurements, enthalpies required for ablation were deduced, and estimates were made of absorption of the laser radiation due to gaseous ablation products. Apparent physicochemical aspects of the ablation peculiar to each composite are described. For Kelvar/epoxy, a significant result was the rapid decrease in ablation enthalpy with irradiance. This is attributed to nonequilibrium decomposition of the organic composite.