Effects of Heat Treatment on Microstructure and Mechanical Properties of AlSi10Mg Fabricated by Selective Laser Melting Process

AlSi10Mg is the most widely additively manufactured and commercialized aluminum alloy and has been used in this study to analyze the effect of heat treatment on its microstructure and mechanical properties. Although research indicates AlSi10Mg parts produced by selective laser melting have characteristically very fine microstructures, there is a need for more intensive study to comprehend the effect of heat treatment on the mechanical properties of this alloy by analyzing its microstructure. In this study, AlSi10Mg specimens heat-treated at varying temperatures were analyzed by optical and electron microscopes. Micro-indentation hardness and tensile tests were performed to evaluate mechanical properties while considering the specimen build orientation. Observation shows that it is nearly impossible to completely dissolve the evolved second phase silicon-rich particles, which may have significant effects on the mechanical characteristics. Electron microscopy images show the evolution of iron-rich particles in the Al matrix, which may have a significant influence on the mechanical properties of the alloy.