Investigation on Laser Ablation Properties of CaCO₃ Coating

Due to its own characteristics, laser has been greatly developed and widely used. Laser threat must be resolved properly with the laser used in the military fields. To protect the substrates and equipments from threats and damage, laser protection is greatly necessary. The laser energy accumulation on the material will cause a terrible problem. At present, the main damage form is thermal destruction of high power continuous laser. When the temperature reaches the threshold of the material, the material will be consumed by oxidation, melting and evaporation. In order to ensure the substrates and equipments away from damage, decreasing the incidence laser energy is an effective way, and in turn decreasing the temperature below the threshold of the material. Therefore, in this paper, a common enthalpy change material, CaCO₃, was studied. The laser damage behavior and protection ability of CaCO₃ coatings were explored. The results show that the substrate back-surface temperature decreased obviously, while CaCO₃ coatings with the thickness of 1mm dissipated effectively of the incident laser energy. From calculation, 0.473 kJ energy per unit area (1 cm²) can be dissipated, and 53℃ can be decreased for the No.45 steel substrate, which agrees with the experimental results.