Fatigue analysis of a progressive secondary A357 alloy with higher iron content in a chloride environment

Abstract

This paper investigates the fatigue behavior of secondary A357.0-T6 alloy with higher Fe content as a result of the usage of recycled metals. Commercial secondary Al-alloys contain Fe, often as an undesirable impurity negatively affecting plasticity, tensile strength, and so on due to the formation of brittle intermetallic phases. A common unwanted intermetallic phase is β-Al5FeSi in form of brittle platelets. This plate-like morphology acts as a stress concentrator, leading to a decrease in the strength, ductility, and dynamic fracture toughness of the castings. Moreover, promoting casting defects such as porosity. In addition to structural and mechanical properties, the corrosive environment also influences fatigue lifetime. The effect of corrosion damage on fatigue failure is a problem for engineers in the aerospace, automotive, and gas or oil industries. The corrosion reactions or their products can interact with the fatigue process accelerating crack initiation or propagation. Therefore, the aim of this study is to investigate chemical-mechanical interactions during the simultaneous application of cyclic stress and exposure to a corrosive environment.