Relationship between Temperature of Baseplate and Fundamental Characteristics of AlSi10Mg Alloy Fabricated by Laser Powder Bed Fusion

In this study, a comprehensive investigation was conducted to reveal the influences of the base plate temperature on fundamental properties of AlSi10Mg alloy fabricated by laser powder bed fusion (LPBF). Concurrently, a meticulous analysis was undertaken to clarify their anisotropy generated through the formation of microstructural texture. The increase in the base plate temperature decreased the residual stress induced on the surfaces of the LPBF materials, but slightly increased the number of defects with relatively large sizes. On the cross-sections of the LPBF materials, a large number of fan-shaped melt pool traces stacked perpendicular to the building direction were observed. As the base plate temperature increased, the spindle-shaped fine microstructure in the fan-shaped melt pools extended to the upper fan-shaped melt pools, and the reticular microstructure along the arc of the melt pools became continuous. Although the static strength decreased with increasing the base plate temperature, the ductility in the building direction improved due to the microstructural changes. Regardless of the base plate temperature, a characteristic anisotropy in the static strength was found due to the formation of the microstructural texture. The decrease in the tensile strength with increasing the base plate temperature resulted in the decrease in the fatigue strength.