Microstructure and Mechanical Properties of SLM AlSi10Mg Alloy

AlSi10Mg alloy is widely used in automotive and aerospace applications due to its high strength-to-weight ratio and excellent corrosion resistance. In this study, the microstructure and mechanical properties of selective laser-melted (SLM) AlSi10Mg alloy were systematically investigated. Residual stress analysis showed compressive stresses of 14-85MPa and shear stresses of 2-30MPa, while FWHM values (~2.6-2.7°) indicated stable microstructural strain. Three-dimensional reconstruction confirmed a pore-free volume of interest (7.63×10¹²µm³) with 100% relative density. SEM revealed a dense and uniform microstructure with well-bonded melt tracks, and EBSD confirmed grain orientation and strain distribution. Nanoindentation showed a hardness of 1.58 GPa and an elastic modulus of 81 GPa, while tensile testing yielded an ultimate tensile strength of 450 MPa. XRD identified FCC Al and Si phases, confirming phase stability. The enhanced performance is attributed to uniform Si distribution and refined microstructure obtained under optimized SLM parameters (200 W laser power, 500 mm/s scan speed, 100 µm hatch spacing, 30 µm layer thickness, and 150 J/mm³ energy density). Overall, the SLM-fabricated AlSi10Mg alloy exhibited a dense microstructure, stable phases, and reliable mechanical performance, demonstrating its suitability for structural applications.

Keywords:

Additive Manufacturing (AM), Selective Laser Melting (SLM), Mechanical Properties, Microstructure Characterization, Porosity, Residual Stress,