Verbesserung des Korrosionsverhaltens von Nietverbindungen an Flugzeugen Abschlussbericht

New surface treatment processes available include modification of the oxide layer on Ti alloys, their coating with Al pigmented resins or IVD coatings, which are currently in use, but expensive; unknown, however, is their behavior under operating conditions. Not only the above coatings but also new base materials such as Al-Li alloy, whose behavior under operating conditions is greatly unknown, must be investigated. The subject of the research project documented here was an investigation of these new pretreatment and protection processes. Tests were aimed at verifying whether protection systems meet the requirements under dynamic and corrosive stresses and thus reduce the maintenance effort involved and extend the service life of aircraft. In addition to standard corrosion tests, electrochemical contact corrosion investigations and electrochemical impedance spectroscopy, particular emphasis was placed upon carrying out tests of riveted joints under alternating mechanical loads with simultaneous corrosive stress. The materials investigated were 2024, 7475 and 8090, in each case joined with TiAl6V4 rivets. New protection systems applied and investigated include unalloyed aluminum sputtered onto the Ti alloy, Ni-Zn coatings electrolytically deposited, Al pigmented chromate-containing and chromate-free resins. The anodized TiAl6V4 surface served as a reference which was to be improved. (orig./RHM)Available from TIB Hannover: F94B2165 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany); Deutsche Gesellschaft fuer Chemisches Apparatewesen, Chemische Technik und Biotechnologie e.V. (DECHEMA), Frankfurt am Main (Germany)DEGerman