Effects of build orientation on mechanical properties of curved-surface AlSi10Mg alloy fabricated by powder bed fusion additive manufacturing

AlSi10Mg alloy has been widely used in the aerospace and automotive industries due to its superior physical and mechanical properties. Most AlSi10Mg components possess complicated-geometrical characteristics, such as planar thin wall, lattice structure, curved surface, etc. In recent years, laser-based powder bed fusion (PBF) has emerged as a promising additive manufacturing technique to produce complex AlSi10Mg alloy parts with a high resolution. PBF of curved-surface components exhibit varied heat transfer conditions, challenging post-fabrication processes, and intricate force conditions during mechanical testing owing to their structural inflections and variable cross-sections. Thus, the mechanical properties of the as-built AlSi10Mg parts with curved surfaces should be comprehensively understood to facilitate the adoption of PBF-built curved-surface AlSi10Mg parts in practical engineering applications. This paper systematically investigated the effects of build orientation on the tensile property and microhardness of the PBF-built AlSi10Mg parts with curved surfaces. The results showed that both bending stress and stretching stress contributed to the overall tensile stress of the curved-surface tensile specimens, and the failure always occurred at the peak/valley locations of the sine curved surface due to the largest bending moment. Meanwhile, the ultimate tensile strength increased with the build orientation varying from 60° to 90°. In addition, the curvatures C2 and C4 presented the lowest microhardness while C1 and C5 showed the highest one.