PSI - Issue 82

Goran Vukelić et al. / Procedia Structural Integrity 82 (2026) 24 – 29 Vukelić et al. / Structural Integrity Procedia 00 (2026) 000–000

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subtractive methods. In marine engineering, AM offers significant potential for producing customized components, on-demand repairs, and topology-optimized structures (Kopic and Mihaljec, 2025). Among materials utilized in marine structures, aluminum alloys occupy a central role due to their high strength-to-weight ratio, good machinability, and inherent corrosion resistance (Basan et al., 2025). These properties make aluminum particularly suitable for ship hulls, superstructures, and various offshore components where weight reduction directly contributes to improved stability, payload capacity, and energy efficiency (Bogdanovic and Ivosevic, 2025; Polemis and Boviatsis, 2023). Additively manufactured aluminum alloys have been widely studied for their mechanical performance and microstructural characteristics under controlled laboratory conditions. However, their long-term durability and integrity in natural marine environments remain less explored. An aggressive marine environment accelerates corrosion and degradation processes. In aluminum, the passive oxide film that normally protects the surface can become locally compromised in saline conditions, leading to pitting, crevice corrosion, and exfoliation (Mostert et al., 2025; Nikitin et al., 2025). The microstructural features inherent to additively manufactured components may further pronounce these degradation mechanisms (Monkova et al., 2024). As a result, the mechanical properties of AM aluminum parts exposed to marine environments can differ significantly from those of conventionally produced counterparts, with potential implications for structural reliability and service life. Although numerous studies have investigated the corrosion behavior of aluminum alloys in simulated or accelerated laboratory conditions (Guo et al., 2025; Mao et al., 2022; Yan et al., 2024), these environments often fail to fully replicate the complexity of natural marine exposure (Dantas et al., 2024). Consequently, there exists a need for experimental studies conducted in real world marine settings to assess the true environmental impact on the mechanical performance of additively manufactured aluminum. This study presents an experimental investigation into the effect of the natural marine environment on the additively manufactured aluminum alloy AlSi10Mg0.6. Specimens were deployed below the sea surface for three and six months at two different locations in the Adriatic Sea. Following the exposure, the specimens were evaluated for changes in mass and tensile strength over time of exposure. 2. Materials and methods Additively manufactured aluminium specimens were submerged below the sea surface for exposure periods of three and six months to assess the influence of the natural marine environment on their corrosion behaviour and to obtain more representative insights than those derived from laboratory-based testing. After each exposure interval, the specimens were retrieved and evaluated for relative mass variation to quantify corrosion-induced material loss, with the results correlated to the respective immersion durations. Standardized testing protocols were subsequently applied to generate engineering stress-strain curves through uniaxial tensile testing, facilitating the assessment of variations in tensile strength. The resulting mechanical data are presented as a function of exposure time. The study was performed on aluminum alloy AlSi10Mg0.6, widely used in additive manufacturing, Table 1. The high silicon content provides excellent castability and enhanced corrosion resistance, while magnesium contributes to precipitation hardening and improved mechanical strength. This alloy offers a favorable balance of low density, high specific strength, and good thermal conductivity, making it suitable for applications in aerospace, automotive, and marine engineering, where lightweight and durability are critical. In the as-built condition, the fine microstructure produced by rapid solidification during AM leads to high hardness and tensile strength, though post-processing is often applied to reduce residual stresses and improve ductility (Calvo-García et al., 2025; Köckritz et al., 2025).

Table 1. Composition of feedstock aluminum powder AlSi10Mg, based on supplier datasheet (w t %). Al Si Fe Cu Mn Mg Ni Zn Pb Sn Ti Balance 9-11 0.55 0.05 0.45 0.25-0.45 0.05 0.1 0.05 0.05 0.15

To prepare the specimens for testing, the Selective Laser Melting (SLM) process was used. The aluminum powder had a particle size distribution between 25 and 70 μm. Specimens were printed in a flat orientation and shot-peened to achieve the final surface finish, Fig. 1a. A total of 25 specimens were made, with five of them retained in the room