Durability Assessment of Additively Manufactured Multi-Material Components for Potential Applications in Structures Exposed to Marine Environments

Abstract

Additive manufacturing enables the production of multi-material components and graded structures that are impractical or impossible to achieve using traditional assembly-based manufacturing. This capability offers significant benefits for applications requiring tailored properties, including components intended for marine environments, such as parts of underwater acoustic recorders used by the Brazilian Navy. In this study, the durability of 3D-printed multi-material structures exposed to seawater was evaluated. Sandwich specimens comprising ABS outer layers and a PLA core were fabricated using Fused Filament Fabrication (FFF). Three configurations were produced with one, three, and five ABS layers. Aging was conducted in natural seawater for 60 days, followed by tensile and flexural testing of both unaged (control) and aged samples. Water absorption behavior was also assessed. PLA exhibited the highest uptake, while ABS showed the lowest. Hybrid specimens absorbed less distilled water than pure PLA, indicating a potential barrier effect of the ABS layers. For unaged samples, tensile and flexural properties increased with the number of ABS layers. After aging, mechanical responses among configurations converged, suggesting a performance plateau due to seawater exposure. These findings support the potential of FFF multi-material structures for marine applications while highlighting the need for improved moisture-resistant design strategies.