Research on the limitations of laser energy density and microstructure characteristics of selective laser melted AlSi10Mg alloy

In this study, deficiencies in using the laser energy density (LED) to combine different process parameters to represent the heat input in selective laser melting (SLM) process are proposed. The change in melt pool shape could not always be clarified by the LED input, since the vary of LED input caused by altering hatch spacing cannot change the melt pool shape. In addition, the microstructure of SLM fabricated AlSi10Mg material was observed, and this paper gives a further elucidation on the formation of the hierarchical microstructures that discriminated by the morphology of Si phase. Microhardness is enhanced by the supersaturated alpha-Al matrix, and the hardness value of coarse zones and fine zones show different performance.