Influence of salt corrosion on the fatigue behaviour of aluminium alloys for chassis components under constant and variable amplitude loading

This paper presents an approach to assessing the cumulative fatigue under spectrum loading and simultaneous salt corrosion for aluminium alloys. Fatigue tests, in air and in 5 % sodium chloride solution, were performed with two different structural aluminium alloys (EN AW-6082 T6 and EN AW-7075 T73) using unnotched and notched specimens. The alloy EN AW-7075 T73 proved to be unsuitable for automotive applications due to its high susceptibility to corrosion. For fatigue lifing, a modified cumulative damage calculation based on the material susceptibility, which comprises the influence of salt corrosion on fatigue lifetime, has been proposed. On this basis, potential structural aluminium alloys for chassis applications can be evaluated and selected, prior to validation tests.