Comparative study of performance comparison of AlSi10Mg alloy prepared by selective laser melting and casting

The influence of the microstructure on mechanical properties of AlSi10Mg fabricated by casting and selective laser melting (SLM) were investigated and contrasted in this work, with an emphasis on understanding the forming mechanism. The microstructure, phase structure and mechanical properties were characterized by scanning electron microscopy/field-emission Transmission Electron Microscopy (SEM/TEM), X-Ray Diffraction (XRD), tensile and fatigue tests. The results indicated that the SLMAlSi10Mg exhibited a supersaturated Si network structure precipitated along alpha-Al cell. Brittle beta-Al5FeSi and pi-Al8FeMg3Si6 phases were found in the as-cast and SLM AlSi10Mg respectively due to different thermal histories during processing. The SLM AlSi10Mg showed higher tensile strength but lower elongation than the casting, as the result of grain refinement and tortuous crack path. The fatigue results revealed that unmelted powder, oxide inclusion and pores can considerably degrade the fatigue properties for the SLM AlSi10Mg. The SLM process offered a new method for material processing that would avoid harmful Fe-bearing intermetallic compounds and refine the microstructures for enhancing strength. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.