Ablation threshold measurement and absorption characteristic analysis of two fiber reinforced composites irradiated by CW laser

The ablation threshold measurement and absorption characteristic analysis in the ablation courses of polyaryl amide-fibers/epoxy and carbon-fibers/epoxy composites irradiated by 1.319 μm continuous wave laser beam were studied by the double integrating spheres-photodiode system and the camera recording method. The results show that the average ablation threshold of polyaryl amide-fibers/epoxy composite decreases with the material thickness increasing, but the thickness does’t effect the average ablation threshold of carbon-fibers/epoxy composite, which is about 70 W/cm2. The reflectivities of two composites increase slowly with the laser power intensity increasing before ablation, and change from 0.40 to 0.45 for polyaryl amide-fibers/epoxy composite and from 0.15 to 0.20 for carbon-fibe