Silver films on aluminum alloy 6061 modified by ion bombardment improves surface reflectivity

Abstract

Aluminum alloy substrates are widely used in military and civilian fields. However, the surface roughness of aluminum alloy materials is relatively large high due to the existence of tool marks after processing, which affects the optical performance. Reflectivity can be improved by Covering the surface of aluminum alloy 6061 with silver films can improve reflectivity. In order to develop long-term stable highly reflective silver films, a protective dielectric layer was first designed, and then deposited by electron beam evaporation. Covering a few more dielectric layers on the silver film, the reflectivity was further improved. Ar + bombarding the surface of the silver film can smooth the surface grains, and use this to evaluate its influence on the reflectivity performance. The reflectivity of the silver film is not only related relates to the evaporation rate and Ar + bombardment, but also related relates to tool marks and surface morphology. Ar + bombardment can significantly increase the reflectance of silver films in the wavelength range of 400–1000 nm at an evaporation rate of 15 Å/s. On the surface of AA6061 substrate, the double sutured layer and ion bombardment on the surface of silver film combined with dielectric interface can isolate the effect of knife marks, which can lead to the improvement of reflectivity.