Ablative Properties of Calcium Carbonate-Filled Phenolic Matrix Composite Coatings Irradiated by High Energy Continuous-Wave Laser

Laser, especially high energy continuous-wave (CW) laser, can destroy traditional structure material of aircrafts or vehicles easily. Therefore, anti-laser damage is gradually becoming a major concern. In this case, calcium carbonate (CaCO₃)-filled phenolic matrix composite coatings have been designed and prepared to prevent from high energy CW laser damage. Laser ablation behavior of the coating is deeply studied by varying the laser parameters including laser power density and irradiation time. The results show that the phenolic resin keeps decomposing into residual char caused by the high temperature during laser irradiation. The porous structure of phenolic resin of residual char provides an excellent thermal insulation property for the coating. In addition, the decomposition reaction of CaCO₃ consumes a large amount of laser energy, which has a cooling effect on the residual char. CaO that is produced during the decomposition of CaCO₃ has a high melting temperature and can lead to the thermal stability improvement of the residual char. Due to the introduction of CaCO₃, the back-surface temperature of sample is decreased from 94 °C to 64 °C when irradiated at 500 W/cm² for 10 s and the anti-laser property of the coating is improved. All the analysis indicate that the designed coating can perform as a shield to prevent from high energy CW laser.