On Laser Powder-Bed Fusion of Additively Manufactured AlSi10Mg Alloy: Tensile Properties and Structure Characterization

Abstract

The mechanical properties of additive manufactured laser powder-bed fusion (L-PBF) AlSi10Mg specimens, built with the chessboard building strategy and followed by three thermal treatments, were evaluated using standard mechanical testing in tension. Metallography and fractography tests were conducted to reveal the microstructure and connect them to the properties in various stages of the research. A strong relationship between hatching strategy, build direction and loading direction was found and it was concluded that the mechanical properties of the alloy in the modified T5 (200^oC) thermal condition are similar to the as-built condition for the concept strategy. The mechanical properties are similar albeit the differences found in the fracture faces of X and Z specimens. The similarity of the mechanical properties in the X and Z directions also suggests that the additively manufacturing (AM) L-PBF process yields fairly homogenous mechanical properties of AlSi10Mg (excluding the T5 treated alloy). The mechanical properties and the microstructure obtained were compared to an equivalent alloy AM L-PBF manufactured using an EOS© system with a different hatching strategy. The three different thermal conditions, employed in this research, provided insight into the mechanical behavior under different strategies. Understanding these changes in mechanical properties, as a result of these thermal conditions, allows for tailoring AM parts for engineering applications having various requirements. The onset of the elastic-plastic deformation and the possible effects of the hatching strategy on the elastic-plastic deformation and the strain hardening behavior were also discussed.