PSI - Issue 83

Sze Pei Tan et al. / Procedia Structural Integrity 83 (2026) 28–40

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1. Introduction The rapidly growing demand for lightweight and complex geometrical components has driven the adoption of metal additive manufacturing (MAM) in advanced engineering applications especially for automotive and aerospace industries [1–3] . In this regards, direct metal laser sintering (DLMS) has become a practical manufacturing route for manufacturing aluminum alloy components that not only enhance the mechanical properties but also combined the geometric flexibility [4, 5] . Unlike the traditional manufacturing techniques, DLMS enables the manufacturing of components directly from computer aided design (CAD) which reduces the material waste and minimizes the post processing. In this regards aluminum alloy like AlSi10Mg is known for its excellent strength- to -weight ratio that makes it suitable for lightweight components manufacturing especially in automotive and aerospace sectors [6–8] . However, the adoption of AM & AlSi10Mg in critical applications is hampered by surface cracks, which compromise structural integrity and fatigue life [9, 10] . Recent studies particularly focused on AlSi10Mg have shown that mechanical properties are highly influenced by process parameters and post-processing treatments. A study on optimizing DMLS process parameters showed that mechanical properties, including fatigue performance, are affected by cyclic loading conditions, tested at a frequency of 10 Hz to evaluate fatigue behavior [5] . A related study by Raja et al. [11] stated that the fatigue behavior of LPBF-fabricated AlSi10Mg stated that tensile and fatigue properties are important indicators, where they indicates variability based on production conditions and test protocols. Although this emphasizes the inherent variability of additive manufacturing but differences in pressure ratios, loading amplitudes, and sample configurations limit direct comparisons in the study. Further investigation of AlSi10Mg has been conducted to assess the fatigue strength with lattice structures produced through AM. The study was aimed to determine the fatigue limit under cyclic loading, emphasizing the importance of mechanical properties in fatigue-resistant design [12] .While valuable for design optimization, such studies do not fully represent the bulk mechanical response of solid DMLS-fabricated components. Another study by Tan et al. [13] stated that post-processing treatments including heat treatment and surface modification have been identified as effective methods to improve the mechanical and fatigue properties of DMLS fabricatedAlSi10Mg. Studies indicate that these treatments can optimize the balance between tensile strength and fatigue resistance, leading to more reliable performance in structural applications [14] . Additionally, Post-processing treatments on heat treatment like stress relief and T6 heat treatment are often applied to enhance mechanical properties. These treatments modify microstructural features, such as coarsening silicon particles or stabilizing grain structures, which can improve hardness, ductility, and thermal stability [15–18] However, existing research prioritizes static properties (e.g., tensile strength) or basic fatigue life measurements [19, 20] with limited attention to surface crack growth behavior. This oversight is critical, as cracks initiating from surface defects or stress concentrations often dictate failure in cyclically loaded components. Therefore, a systematic assessment of the tensile and fatigue life behavior of DMLS-fabricated AlSi10Mg under comparative test conditions is needed. For reliable structural evaluation and engineering applications, it is essential to establish clear baseline mechanical data for both as-built and heat-treated conditions. In this regards, this study aim to investigate the mechanical properties of DMLS fabricated AlSi10Mg under tensile and fatigue loading conditions. In particular, this study evaluates the tensile properties and fatigue life performance of specimens produced in the as-built and heat-treated condition. 2. Experimental Setup Initially the specimen was modeled using CAD software and saved as STL file then the STL file was imported into AM machines computer after that the specimen was prepared using AlSi10Mg by DMLS techniques and the built orientation of the specimen was horizontal. Then the EOS M290 was manufactured using a direct metal laser sintering (DMLS) machine equipped with a 400-watt Yb-fiber laser operated under an argon atmosphere to prevent oxidation. The machine has a maximum build volume of 250 mm × 250 mm × 325 mm and a laser focal diameter of 100 µm. AlSi10Mg powder was used as the feedstock material. The processing parameters applied during fabrication are summarized in Table 1. After the build process was completed, the samples were removed from the build platform and separated from the support structure using cutting tools. Surface finishing was performed where