Study On The Preparation And Anti-laser Ablation Performance Of Inorganic Coating On The Epoxy Resin Matrix Composites Substrate

Higher requirement is put forward on the anti-laser ablation performance of aircraft skin,because of the rapid development of laser weapons.Preparing an inorganic coating on the surface of components is an effective method to improve the laser irradiation resistance.The preparation and anti-laser ablation performance of coating was investigated.The inorganic slurry was prepared with the water glass as binding agent,SiO₂ and Na₂SiF₆ as curing agent,YSZ,Y₂O₃ and Al₂O₃ as filler,and the coating was prepared with the blade coating method on the carbon fiber reinforced epoxy resin matrix composites substrate.The curing process of slurry and characteristics of coating were analyzed by SEM,XRD,IR and Ultraviolet-Visible-Infrared spectrophotometer and so on.The laser irradiation tests were carried out with the wavelength of 1064nm.The preparation process and formula were optimized,and the protective effect and ablation regulars were analyzed.The research results show that,when the modulus of water glass was 2.7,the roughness of coating was smaller and the coating was more compact with less defects.When the modulus was too big or too small,the coating was more defects.The curing of coating was based on dehydration synthesis among the silicon hydroxyl.The curing rate of SiO₂ was slower,and the curing reaction was complete.However,the curing rate of Na₂SiF₆ was faster,and the curing reaction of slurry was not complete.When the curing process was RT/12h and 100℃/10h,the dehydration synthesis among the silicon hydroxyl was complete and the coating was compact.When the filler were YSZ+Y₂O₃ and Y₂O₃,the adhesive strength were both higher,about 5.0MPa and 5.1MPa.When the filler was Al₂O₃,YSZ+Y₂O₃ or Y₂O₃,the coating was more compact.The mass ablation rate was below 0.005g/s after laser irradiation,and the reflection of coating was above 90%.During the laser irradiation,the FSC was higher and stable and the rear surface temperature was lower.So the energy of laser was consumed by reflecting,insulating from heat,and a certain degree of conducting heat.The coating whose filler was YSZ+Y₂O₃ had better anti-laser irradiation,after irradiated by the laser with energy of 2000W for 10s,did not produce obvious ablation mark and the highest rear surface temperature was 41℃.When the filler was YSZ,YSZ+Al₂O₃,Al₂O₃ or Y₂O₃,there were obvious ablation marks and the highest rear surface temperature was 53℃,95℃,87℃and 60℃.After laser irradiation,the ablation of coating was based on the melting and vaporization,and vaporized material cooled down rapidly to form needle-like structures in lower temperature zone.