Effects of Surface Finishing Procedures on Corrosion Behavior of DMLS-AlSi10Mg_200C Alloy Versus Die-Cast A360.1 Aluminum

In this study, the impact of surface finishing procedures on the corrosion resistance of an AlSi10Mg_200C alloy manufactured through direct metal laser sintering (DMLS) versus its die cast counterpart was investigated. The as-printed DMLS-AlSi10Mg_200C and as-cast A360.1 alloys were subjected to various surface finishing processes including grinding and sandblasting. The corrosion performance of the surfaces was then evaluated using a potentiodynamic polarization test and electrochemical impedance spectroscopy in an aerated 3.5wt.% NaCl solution. The results highlighted the better corrosion resistance of DMLS-AlSi10Mg_200C than its cast counterpart with a similar surface finish. The grinding of both as-printed DMLS and as-cast samples was found to initially deteriorate the corrosion performance of the surface by exposing cathodic sites to the electrolyte. However, for longer immersion times and after complete repassivation of the surface, the ground surface showed the highest resistance to the selective attack. The sandblasting process was found to have a detrimental effect on the corrosion resistance of both alloys.