On the microstructures and electrochemical studies of sintered and selective laser melted AlSi10Mg alloy in chloride environments

In this study, aluminum alloys (AlSi10Mg) were fabricated using the spark plasma sintering technique (SPS) and selective laser melting technique (SLM). The sintered AlSi10Mg was consolidated at an optimized parameter: sintering temperature of 500 °C, pressure of 50 MPa, heating rate of 100 °C/min, and holding time of 5 min. The SLM AlSi10Mg alloys were produced at different laser powers ranging from 200–250 W, at the scanning speeds of 800 mm/s and 1200 mm/s. The corrosion behavior of the consolidated samples was determined using NaCl and HCl solutions. The open-circuit potential (OCP) was run for 2 hrs., and potential dynamic polarization (PDP) was determined at −1.0 to 1.0 V. The results show that the sintered AlSi10Mg sample had a homogeneous microstructure of the Al matrix with randomly dispersed Al and Si precipitates. In contrast, the SLM AlSi10Mg samples had finer microstructure with cellular dendrite of Al matrix with inter-dendritic Si particles. The SLM AlSi10Mg sample shows better corrosion resistance than the spark plasma sintered sample in both solutions. The corroded surfaces depict cracks and oxide formation.