Surface Modification of Aluminum Alloys by Two-Stage Passivation in Solutions of Vinyltrimethoxysilane and Organic Inhibitors

Abstract

The protective ability of films formed on Al alloys from solutions of vinyltrimethoxysilane and organic corrosion inhibitors, such as sodium salts of oleyl sarcosine and dioctyl phosphate, has been evaluated by electrochemical and corrosion methods. It is shown that layer-by-layer treatment significantly increases the efficiency of passivation not only with individual components, but also with mixtures thereof. The protective ability of the resulting coatings has been evaluated by the express method (droplet test method) and tests in a humid atmosphere and salt spray chamber. The thicknesses of the obtained CI layers on the surface of Al alloy D16 has been estimated using the ellipsometric method.