| Abstract Scope |
Wire Arc Additive Manufacturing (WAAM) has emerged as a promising technique for fabricating large-scale metallic components with high material efficiency. Nickel Aluminum Bronze (NAB), a widely used alloy in marine and industrial applications, is particularly susceptible to corrosion fatigue due to its exposure to aggressive environments. This study investigates the corrosion fatigue behavior of WAAM-produced NAB under two different ex-situ testing methodologies: conventional servo-hydraulic and ultrasonic fatigue. Ex-situ corrosion fatigue experiments were conducted in a simulated seawater environment to evaluate fatigue behavior. Conventional servo-hydraulic testing (at low frequencies of 10 Hz), and ultrasonic fatigue testing (at high frequency of 20 kHz) were performed on pre-corroded WAAM NAB specimens. Fractographic and microstructural analyses were carried out using scanning electron microscopy (SEM) and optical microscopy to assess the effects of corrosion on fatigue crack growth. Results revealed that WAAM NAB exhibits a complex interaction between microstructural heterogeneity and environmental degradation. The study highlights the impact of surface corrosion and WAAM-induced defects on fatigue performance, with implications for the long-term durability of NAB components in marine applications. These findings, along with ambient air fatigue results on virgin specimens, contribute to understanding the fatigue behavior of WAAM NAB under corrosive conditions, providing valuable insights for optimizing WAAM processing parameters to enhance performance. This research underscores the need for further studies on in-situ corrosion fatigue to better replicate service conditions. |