Thin Solid Films, Vol.619, 202-207, 2016
Development and degradation behavior of protective multilayer coatings for aluminum reflectors for solar thermal applications
The fabrication of multilayers Al-SiO2, Al-SiO2-TiO2, Al-Ni-Ag-SiO2, Al-Ni-Ag-SiO2-TiO2 on anodized aluminum sheet by the combination of physical vapor deposition sputtering and sol-gel coating process has been done. The multilayers of very high reflectivity (95% or more) could be developed on Al. The Al mirror reflectivity has been enhanced to 95% by a thin coating of Ag on aluminum in between the substrate and transparent and protective layers of SiO2 and SiO2-TiO2 The degradation behavior of these multilayers in accelerated weathering condition and under salt spray with different hours of exposure vis a vis reflectance is investigated. These coatings showed higher reflectance and sustenance in accelerated weathering and salt spray environment making it potential multilayered coating for solar thermal applications. (C) 2016 Elsevier B.V. All rights reserved.