Infrared Emissivity Of CeO₂/Resin Composite Coating In 8¹4μm Waveband

In modern war,low infrared emissivity coatings have received extensive attentions due to its protection for military targets.At present,the coatings which own low emissivity in 8¹4μm waveband and good engineering application performance are mainly composed of metals whose temperature resistance and corrosion resistance are weak and the emissivity of the coating would be enhanced in return with the deterioration of application environment.Also,the high gloss and high permittivity of metal-based low infrared emissivity coating limits its possibility of compatible stealth.By comparison,the gloss and permittivity of semiconducting metal oxides is relatively low and make it be the potential candidates for infrared and radar compatible materials.Nevertheless,the emissivity values of metal oxide-based coatings are still high in 8¹4μm waveband which weakens its infrared stealth performance.In this paper,CeO₂ and resin were introduced as the filler and binder respectively.Screening and modification as well as the regulation of interface compatibility of them were conducted to decrease the infrared emissivity of the coating in 8¹4μm waveband.The obtained researching works and results are as follow:1.CeO₂ prepared by solid-phase synthesis was chosen as the filler of the coating by the analysis of microstructure and comparison of emissivity between it and hydrothermal sysnthesized CeO₂.By comparison of the comprehension performance between the coatings prepared by several binder,epoxy silicone resin was introduced as the binder of the coating because of its temperature resistance,mechanical property and low emissivity.At last,the ratio of filler to resin was adjusted to 7:3 to maintain the overall performance of the coating.2.CeO₂ powders with flaky morphology and high floating rate fabricated by ball-milling and modification to decrease the coatings’emissivity.Influences of ball-milling time,content of surfactant on the emissivity of the coating were investigated systematically.The results indicated that the coating with CeO₂ fillers ball-milled by 4 hours and modified by 1 wt%of stearic acid exhibits the lowest emissivity value of 0.831 compared with the initial 0.961 in the 8¹4μm waveband.3.Based on the influence of interface compatibility between CeO₂ fillers and resin on the emissivity of the coating,MAH was introduced to modify the epoxy silicone resin to enhance the interface compatibility and reduce infrared emissivity.Results show that MAH increased the polarity of resin,the interface compatibility between CeO₂ fillers and resin was enhanced and the emissivity of coating was decreased eventually and reached to the minimum value 0.811 when the content of MAH is 5%.By comparison of CeO₂ based composite coating and metal Al based coating,the dielectric properties and floating performance is the key factor of coating’s emissivity.