Variations in microstructure and mechanical properties of selective laser melted AlSi10Mg alloy with different heat treatments

Abstract

In the present study, the variations of precipitated phases, microstructure and mechanical properties of different heat treatments were investigated. The main precipitated phases were Al and Si in different heat-treated specimens. The horizontal microstructures of as-deposited and below 280°C annealing appeared the interwoven structures, and the vertical microstructures were fish-scale structures. As the annealing temperatures were higher than 280°C, the interwoven and fish-scale structures disappeared because the Si phase precipitated and coarsen along the boundaries. With regard to the specimen was heat-treated by solution + artificial aging (T6), the strengths increased and ductility decreased, respectively compared with those of specimens at 420°C for 2 h. Moreover, The AlSi10Mg specimen annealing at 280°C for 2 h has excellent strength and ductility. This investigation indicates that the microstructure and mechanical properties of SLM AlSi10Mg alloy be tailored by different heat treatment processes.