Analysis of the Mechanical Properties of Anodized Al-Si Alloys

Abstract

Aluminum alloys have been widely used in multiple applications, such as in civil construction and engine pistons. They are subjected to loads that may impair their mechanical properties. Thereby, this research aims to study the influence of anodization on the mechanical properties of alloy samples and evaluate the behavior of oxide films when subjected to tensile testing. The mechanical properties of specimens have been evaluated based on tensile and Knoop hardness tests, and strain, tensile strength, and modulus of elasticity of specimens have been determined based on the stress-strain curve. The morphology of oxide films was analyzed by scanning electron microscopy (SEM) and optical microscopy (OM). Results of anodized Al-Si alloys in both modes, i.e. pulsed and direct currents, were compared, and it was found that pulsed current was more efficient than direct current with respect to uniformity of the formed film, and that the anodization process can affect a few mechanical properties of samples. The tension testing results also revealed that the oxide film has been fractured perpendicularly towards traction. However, the oxide film hardness was not affected by the anodization mode (pulsed or direct currents). In addition, a heat treatment was efficient at improving the uniformity of anodic films.