Incorporation of Corrosion Effects into the Life-Cycle Analysis of AW-2017A-T4 Aluminium Alloy under Bending Moment

Abstract

The paper presents the results of fatigue tests of corroded AW-2017A-T4 aluminium alloy samples subjected to an alternating (symmetrical) bending load. Although there are a number of works describing pre-corrosion fatigue in aluminium alloys, relatively few of them concern bending fatigue effects, in some selected alloys only. Here, the AW-2017A-T4 samples were exposed to electrochemical preliminary corrosion by immersion in an electrolyte, a 3.5% solution of NaCl in water. Several variants of series of samples differing in immersion time were tested. Based on the analysis of the results obtained, Basquin’s fatigue characteristics were developed and compared to the characteristics of the material in its nominal state, which allowed for conclusions on the influence of corrosion effects. The characteristic curves show the susceptibility of the test material to corrosive processes, which results in a decrease in fatigue life along with the increase of pre-corrosion time. The samples with longer immersion duration revealed larger surface losses and widespread corrosion pits.