Untersuchung von Aluminium 6xxx Blechen für Außenhautanwendungen im Automobil auf die Empfindlichkeit gegenüber Wurmkorrosion infolge des Schleifens der Oberfläche

Translated title of the contribution: Investigation on the susceptibility to filiform corrosion of aluminum 6xxx sheets used for exterior body applications caused by surface grinding

Anton Trautmann

Research output: ThesisDiploma Thesis

4064 Downloads (Pure)

Abstract

The growing demand of lightweight construction concepts in the automotive sector has led to an increased usage of light metals. In the area of the exterior body panels, hardenable aluminum alloys of the 6xxx family are used. After joining the so-called „body in white“ (BIW) and before the paint-bake process, it is often necessary to grind the surface of the sheet metal. In case of a damaged coating, progression of corrosion beneath the protective layer may occur, especially in aggressive atmospheres. In the present work, results from electrochemical measurements, filiform corrosion tests and transmission electron microscopic (TEM) investigations on 6xxx alloys – with different copper contents – are presented. Various surface and heat treatment states of these alloys are characterized and compared with each other regarding their corrosion potential, their microstructure and their susceptibility to filiform corrosion. Based on the presented results, an electrochemical "rapid test" is recommended, by means of which ground sheets of high-strength aluminum 6xxx alloys can be classified with respect to their susceptibility to filiform corrosion. Thus, a time-intensive filiform corrosion test is obsolete.
Translated title of the contributionInvestigation on the susceptibility to filiform corrosion of aluminum 6xxx sheets used for exterior body applications caused by surface grinding
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
  • Oberhauser, Paul, Supervisor (external), External person
  • Mori, Gregor Karl, Supervisor (internal)
Award date7 Apr 2017
Publication statusPublished - 2017

Bibliographical note

embargoed until null

Keywords

  • aluminum
  • 6xxx
  • AlMgSiCu
  • Al-Mg-Si-Cu
  • filiform corrosion
  • corrosion
  • automotive
  • exterior body applications
  • corrosion potential
  • electrochemistry
  • near surface deformed layer
  • fine-grained layer
  • grinding

Cite this