Study On Surface Antireflection Coating Of Aluminum Alloy

In order to effectively solve a series of problems such as the shortage of fossil resources and environmental pollution,people pay attention to the energy conservation,environmental protection and economic solar energy,so the development of solar energy technology,the commercial production of solar equipment has been gradually paid attention to.Aluminum is now making the main material of plate type solar water heater,including collector heat-sink plate and frame,and the amount of solar energy water heater installation and one of the world's leading level but as a result of aluminum is high reflectivity material,when as a collector of basement,coating is carried out on aluminum surface treatment,to control the reflection index of the aluminum surface,improve the utilization efficiency of solar energy.In this paper,silicone resin was used as binder,and MnO2 nano powder and graphene sheets were used as absorbent to spray a low cost antireflection coating(ARC).The effects of particle size,concentration and spraying time on coating properties were discussed.The performances of two kinds of solar anti-reflection coatings were compared and analyzed.The TG/DSC thermal analyzer was used to analyze the thermogravimetry and thermal difference of the coating and test the thermal resistance of the coating.Scanning electron microscope(SEM)was used to analyze the surface morphology of the sample and the effect of coating surface morphology on the anti-reflection performance;The absorbance was calculated from the reflection data measured by uv-visible spectrophotometer and the emissivity was measured by infrared spectrometer.Specific work contents and results are as follows.1.The binder can withstand temperature of 300?,suitable for low-temperature solar energy application;Considering the optical properties and economic cost of the coating,graphene microsheet and MnO2 micro nano powder were selected as solar absorbent materials The aluminum alloy substrate was tribally treated as 90s,and the coating was prepared by spraying.2.Controlled the ball grinding time,concentration and spraying time of MnO2 micro nano powder,and observed and tested its influence on the optical properties of the coating The results showed that:MnO2 micro nano powder was mown for more than 10 hours,the spraying time was 8s,and when the MnO2 micro nano powder was added to a certain concentration(50%),the reflectance of the coating was the lowest,the absorption rate was 0.983,and the emissivity was 0.455.The coating has good optical properties.3.Control the size,concentration and spraying time of graphene microsheets,and observe and test the influence of graphene microsheets on the optical properties of the coating.The experimental results showed that when the graphene microsheets screened with 400 mesh were selected,the addition amount reached a certain concentration(25%)and the spraying time was 6s,the coating had the best anti-reflection performance,the absorption rate was 0.980 and the emissivity was 0.384.4.The results showed that the absorptivity of MnO2 nano powder was similar to that of the two coatings,but the emissivity of the graphene coatings was lower(0.384).The ?=2.55 Moreover,the surface and absorptivity of the graphene coatings were not significantly changed after being treated at 300?,which could meet the practical requirements of a low-temperature solar collector.