Analysis of contributions of plastic deformation and intergranular corrosion to corrosion-fatigue failure of Al-Mg alloys

TL;DR

This study investigates how plastic deformation and intergranular corrosion contribute to corrosion-fatigue failure in Al-Mg alloys through experimental testing in air and saline solution.

Contribution

It identifies the dominant failure mechanisms at different stress levels and models fatigue behavior using the Basquin equation and crack tip plastic deformation.

Findings

Pitting and intergranular corrosion dominate at low stresses.

Plastic deformation at crack tips is significant at high stresses.

Fatigue behavior can be modeled with established equations.

Abstract

The article presents the results of corrosion-fatigue tests of industrial Al-Mg alloys were conducted in air and in a 3% NaCl aqueous solution. Fatigue curves can be characterized using the Basquin equation and the plastic deformation model at the crack tip. It has been demonstrated that the primary contributions to corrosion-fatigue failure in the Al-Mg alloys at low stresses are made by the process of pitting and intergranular corrosion, and by the plastic deformation at high stresses.