Development of Corrosion Protection Coatings for AA2024-T3 Using Micro-Encapsulated Inhibitors

The paper describes the development of a chromate-free self-healing corrosion protection coating for high strength aluminium alloys. The concept for this approach is based on using inhibitor loaded microcapsules incorporated in the paint film. The capsules are produced by means of interfacial polymerisation. The capsules and the loaded paints are characterised by Scanning Electron microscopy (SEM), Thermal Gravimetric Analysis and Differential Scanning calorimetry (TGA/DSC). The barrier properties and the active corrosion protection properties on AA2024-T3 are studied using Electrochemical Impedance Spectroscopy (EIS), Scanning Vibrating Electrode Technique (SVET) and standard corrosion tests. Encapsulation of inhibitors improves the effectiveness by increase of inhibition capacity and compatibility to organic paint primers.