Surface modification and cutting of carbon composites and carbon fabrics under the action of laser radiation

The main features of use of laser radiation for a surface modification and cutting of carbon composites and carbon fabrics were considered. The effect of laser treatment in air, argon, helium and vacuum on microstructure of a carbon fabric reinforced carbon/carbon composite with non-graphitising carbon matrix was investigated by X-ray diffraction. The change of microstructure of carbon composite after laser treatment was characterized by appearance of hexagonal and rhombohedral graphite phases. The percentage contents of graphite phases depend on parameters of laser processing. An experimental investigations of getting of protective high temperature coatings on carbon/carbon composites by means of laser cladding were accomplished. The reactionary formation of coatings was investigated during laser melting of powders Si - C and Si - Mo. The optimum parameters of processing, structures and thickness of protective layers were determined. The main features of laser-beam pattern cutting by pulserecurrent and continuous. wave laser radiation of carbon plastics, carbon/carbon composites and carbon fabrics were analyzed. It is shown that the use of pulse-recurrent laser radiation for cutting of carbon composites allows essentially to lower or completely exclude a thermal-influence zone and improve quality of cutting. Laser method is the best for cutting of carbon fabrics.