Objective Corrosion of Al has to be counteracted by first anodizing the Al parts and applying further protective coatings. During anodizing, aluminium reacts with the electrolyte and a layer of aluminium oxide is formed on the surface of the aluminium specimen. This coating is highly porous and is subject to attack from the environment and corrosive elements. Therefore, anodized aluminium is normally further processed with a sealing as a final step after anodizing. A hot water sealing process is one of the widely used methods. However in order to close (seal) the pores in the aluminium oxide anodized layer for corrosion protection a process involving boiling water containing chromate is still commonly used. Cr(VI)-based sealing solutions have been employed for several decades, but remain one of the most effective and commonly-used methods to improve corrosion resistance of anodized aluminium. Alternative sealing methods have also been proposed for example with Ni(II), Co(II), Ni(II) and Co(II), rare earth salts, alkali metal fluorides, alkanolamine salts of phosphonic acids, Cr(III), fatty acids, silicates, etc. Already about 45 of the 92 naturally occurring elements have been considered as replacements for Cr(VI) in conversion coatings on aluminium. In general these approaches have not been as successful as the Cr(VI) sealing. Also it should be noted that Ni(II), Co(II) and fluorides are not without health implications, whereas most organic molecules would be expected to have limited lifetimes under the extreme conditions (UV radiation, low pressure, large temperature range) experience by commercial aircraft during operation. Therefore, of the previously identified approaches Cr(III)-containing or silicate-forming sealing solutions in REACH compliant processes are preferred options. An adaption of the electrical TSA cycle for improved corrosion resistance without negative impact on fatigue life of components will be developed. Detailed investigations and characterization of the obtained corrosion protected surfaces via ESEM, Raman + IR-spectroscopy and ESCA will be performed. Fields of science natural scienceschemical sciencesinorganic chemistryalkali metalsengineering and technologymechanical engineeringvehicle engineeringaerospace engineeringaircraftnatural sciencesbiological sciencesbiochemistrybiomoleculeslipidsnatural scienceschemical sciencesinorganic chemistrypost-transition metalsengineering and technologymaterials engineeringcoating and films Programme(s) FP7-JTI - Specific Programme "Cooperation": Joint Technology Initiatives Topic(s) JTI-CS-2011-1-ECO-01-020 - Chromate-free sealing of TSA Call for proposal SP1-JTI-CS-2011-01 See other projects for this call Funding Scheme JTI-CS - Joint Technology Initiatives - Clean Sky Coordinator CEST KOMPETENZZENTRUM FUR ELEKTROCHEMISCHE OBERFLACHENTECHNOLOGIE GMBH EU contribution € 75 000,00 Address VIKTOR KAPLAN STRASSE 2 2700 Wiener Neustadt Austria See on map Region Ostösterreich Niederösterreich Niederösterreich-Süd Activity type Research Organisations Administrative Contact Erich Kny (Dr.) Links Contact the organisation Opens in new window Total cost No data
