Abnormal corrosion behavior of selective laser melted AlSi10Mg alloy induced by heat treatment at 300 °C

Heat treatment is often employed to control the mechanical properties of selective laser melted (SLMed) AlSi10Mg, which also alters its microstructure and corrosion resistance. Therefore, a SLMed AlSi10Mg alloy was heat treated at 300 degrees C and 400 degrees C for 2 h to investigate its microstructural evolution and corrosion behavior. Abnormal corrosion behavior is observed in the sample heat treated at 300 degrees C. Heat treatment destroys the cellular Si network in the microstructure of the SLMed AlSi10Mg sample and promotes the formation of extremely fine Si particles; in contrast, such a microstructure cannot form a protective film on the surface of the sample, which leads to rapid corrosion along the cracked Si network inward to the inner Al matrix without the microgalvanic effect. (C) 2019 Elsevier B.V. All rights reserved.