Evolution of Microwave Transmission Decay in Glass Fiber Reinforced Epoxy Composite Induced by Laser Ablation Carbonization

Experimental research is conducted on the relationship between the graphitic crystallite in the ablation glass fiber reinforced epoxy composite and the microwave transmission decay at a frequency of 10GHz. Ablation samples are prepared by intense laser irradiation of 100W·cm-2 for different time. The microstructure and component of the ablation samples are characterized by means of X-ray diffraction and Raman spectra. The electromagnetic characteristics are investigated by vector network analyzer at 10GHz. When laser of 100W·cm-2 irradiated the samples shorter than 8 seconds, the microwave transmission decay remain small. Beyond 8 seconds, the graphitic crystallites are detected and the microwave transmission decay escalated. With increasing irradiation time, the size and quantity of graphitic crystallites , as well as the microwave transmission decay increase. In brief, we conclude that the generation of graphitic microcrystallites induced by laser irradiation lead to the microwave transmission decay.