PSI - Issue 72

Aria Pranata et al. / Procedia Structural Integrity 72 (2025) 383–391

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Mechanical tests were performed to evaluate the tensile strength and hardness of the joints. The results revealed that placing the softer AA1200 alloy on the advancing side, with a rotational speed of 1500 rpm, achieved the highest tensile strength of 152.48 MPa and a maximum hardness of 97 HV. Non-optimal material placement or rotational speeds led to defects, including voids and poor material mixing, which compromised mechanical performance. This research emphasizes the importance of optimizing process parameters and material placement to improve the mechanical properties of FSW joints (Attah et al., 2022). Wan et al. (2024) investigated the effects of welding parameters, joint geometry, and weak zone properties on the tensile properties of Tungsten Inert Gas (TIG)-welded joints in 2219-T8 aluminum alloy. Using a machine learning model based on the Kriging-Whale Optimization Algorithm (WOA), the research successfully predicted and optimized the ideal weld geometry, achieving a tensile strength of up to 320 MPa and elongation of 4.5%, with a joint strength coefficient of 70%. Fig. 5 illustrates the results of this optimization, showing that the tensile fracture occurred at the front weld toe, away from the fusion line, indicating reduced stress concentration in the Weld Zone (WZ) and Partially Melted Zone (PMZ). The strain distribution was more uniform across the joint, with lower strain concentration at the weld toe, contributing to delayed material failure and improved load-bearing capacity (Wan et al., 2024).

Fig. 5. Tensile fracture in 2219-T8 aluminum alloy (Wan et al., 2024).

These studies emphasize the crucial importance of microstructural management, weld geometry optimization, and selecting appropriate welding parameters to enhance the performance of aluminum alloys in patrol boat applications. With these approaches, welded joints can be designed to minimize damage from stress concentrations and microstructural defects, extending the service life of structural components and ensuring the reliability of patrol boats in extreme operational environments. 5. Concluding remarks The reviewed studies reveal the richness and diversity of research on material degradation in aluminum alloys, particularly in the context of maritime applications. The investigations highlight critical challenges, including corrosion-induced degradation such as pitting, intergranular corrosion, and stress corrosion cracking (SCC), as well as welding-related weaknesses in the weld zone (WZ) and the heat-affected zone (HAZ). These findings demonstrate the complex interplay of environmental, mechanical, and microstructural factors that collectively compromise the reliability of aluminum alloys in harsh maritime environments. Innovations such as friction stir welding (FSW), laser welding, and the optimization of alloy compositions and protective coatings reflect the progress made in addressing these challenges. However, the variability of real-world conditions and the evolving requirements of patrol boat applications underscore the need for continuous research. Future studies should focus on developing advanced alloys with improved resistance to both corrosion and welding-induced degradation, environmentally friendly protective coatings, and predictive modeling tools using machine learning to optimize performance under specific operational