Investigation of the Effects of Surface and Heat Treatment on the Corrosion Behavior of Additively Manufactured AlSi10Mg

ABSTRACT

This work investigates the influence of surface finish and heat treatment on the corrosion behavior of additively manufactured (AM) AlSi10Mg to provide practical recommendations for manufacturing and post‐treatment. Potentiodynamic measurements compare typical characteristic values such as corrosion potential and pitting potential for different material conditions (roughness, heat treatment) and varied chloride concentration of the electrolyte, while scanning electron microscopy characterizes corrosion effects on the microstructure. Fully polished samples show the highest pitting potential and largest passive areas, as surface roughness and low resistance of the thermal oxide layer reduce corrosion resistance in as‐built samples. Stress relief at 300°C increases corrosion potential and lowers corrosion rate but reduces pitting potential due to dissolution of the silicon network presenting large local cathodic areas. T6 treatment shows the worst performance with immediate corrosion after passing the corrosion potential, caused by coarsened Si particles and cathodic Mg ₂ Si precipitates.