Corrosion inhibitors for silane systems on aluminum alloys
Abstract-Organofunctional silanes have been proposed as pretreatments for corrosion protection. However, the silane films inherently lack self-healing properties to protect the exposed surface from damage to the coating. Thus, there is a need for modification and development of more complete silane-based systems. Our work focuses on the incorporation of a combination of inhibitors into silane films in order to achieve such properties. Silane films were modified using a wide range of watersoluble inhibitors. The films were then studied and tested for their effectiveness as pretreatment. Some inhibitors were modified by plasma polymerization techniques for inducing slow-release properties. Various testing and characterization methods were employed to demonstrate the corrosion protection of the substrate over longer periods of time and to unravel the underlying mechanisms. Some corrosion inhibitors and their combinations are found to be effective in corrosion protection when incorporated in a silane film or a thicker silane-based primer coating. Plasma polymerization techniques are shown to be a good method to modify the surface properties of pigments and thus induce a slow-release effect.