Design,preparation And Properties Of Silver High Reflective Film On Aluminum Alloy Substrate

Aluminum alloy substrate has a wide range of applications in the context of the rapid development of science and technology in the new era,and its high reflection characteristics as the main mirror materials play a significant advantage in military attack and civil monitoring.However,the surface roughness of aluminum alloy materials is relatively large due to the existence of knife marks after processing,which affects the optical effect to a certain extent,and the reflectivity is not as good as that of silver in the visible to infrared range.In order to manufacture an optical system with higher reflectivity,we should consider depositing a high reflective composite silver film on the surface of aluminum alloy 6061 to improve the reflectivity.In order to achieve the appropriate reflectance index,the silver high reflective film was deposited on the substrate with different surface quality to feed back the processing index of aluminum alloy;at the same time,in order to improve the reflectance effect,based on the traditional electron beam evaporation preparation process,the Ar + bombardment was used to flatten the convex grains brought by knife grain after the deposition of silver film.Through the optical design software,different high reflection film systems are designed for simulation and comparison,and the influence of the thickness of each film,the optical performance of dielectric film and the oblique incidence on the reflectivity effect is analyzed.Electron beam evaporation is used for the design of optimum reflectivity.The surface roughness,grain morphology and reflectivity of the substrate samples under different deposition and bombardment conditions were measured,and the principle was analyzed.Through the comparative analysis of reflectivity and grain morphology,it is found that the reflectivity of silver film with high evaporation rate is higher when it is not bombarded,and Ar + bombardment can smooth the grain on the surface of silver film,but at the same time,it will highlight the knife pattern on the surface of the substrate,which is contradictory to the effect of reflectivity.The improvement effect of Ar + bombardment is limited by the evaporation rate of silver,and only the reflectivity of the silver high reflective film with the rate of 15?/s is improved obviously.At the same time,the reflectivity requirement is more tolerant to the processing of aluminum alloy.The sample with surface roughness of 0.029 ?m can meet the reflectivity requirement.