Effect of Post-heat Treatment on the Corrosion Behavior of AlSi10Mg Alloy Produced by Additive Manufacturing

Abstract

Additive manufacturing processes are becoming attractive technologies for producing complex components in relatively a short time and at reasonable cost. The present study aims to evaluate the effect of post-heat treatment on the corrosion performance of AlSi10Mg alloy produced by selective laser melting (SLM). Heat treatment up to 400°C for 2 h was tested. Microstructure evaluation was carried out using optical and scanning electron microscopy, along with x-ray diffraction assessment and photoelectron spectroscopy analysis. Corrosion performance was studied by salt spray testing, potentiodynamic polarization and electrochemical impedance spectroscopy for general corrosion assessment, while slow strain rate testing and low cycle corrosion fatigue were employed for stress corrosion examination. The obtained results indicated that relatively improved corrosion performance was achieved by heat treatment at 200–300°C. This was mainly attributed to the preservation of the fine Si net embedded in the α-Al matrix that was obtained during the SLM process and the adequate residual stress relief conditions.