Fatigue endurance and crack propagation under rotating bending fatigue tests on aluminum alloy AISI 6063-T5 with controlled corrosion attack

Rotating bending fatigue tests were carried out on the aluminum alloy 6063-T5 for pre-corroded and non corroded specimens. Special attention was devoted to fatigue endurance reduction induced by controlled surface corrosion on testing specimens. Corrosion attack was obtained by immersion of specimens in an acid solution for: two, four and six minutes in order to induce three degrees of surface corrosion. The corrosion agent was a solution of hydrochloric acid with a pH close to 0.8 and solution concentration of 38%. Rotating bending fatigue tests at the frequency of 75 Hz, room temperature and without environmental humidity control were carried out on the pre-corroded and non corroded specimens in order to investigate the corrosion effect on the fatigue endurance and the stress intensity factor range threshold. Additionally, numerical crack propagation investigation was carried out using a 2D model for testing specimen and the Displacements Correlation Method (DCM). A Kitagawa–Takahashi diagram for this aluminum alloy is developed in the last section of this work; it was obtained with experimental results. Finally, conclusions are listed concerning rotating bending fatigue tests, crack propagation and fatigue-corrosion behavior of this material.

► Controlled corrosion effect on fatigue life.
► Rotating bending fatigue endurance reduction on pre-corroded specimens.
► Crack growth behavior for pre-corroded and non corroded specimens.
► Fatigue failure and non failure zones represented in a Kitagawa–Takahashi diagram.