Fatigue response of wire-arc additive manufactured nickel-aluminum bronze in the annealed condition

Nickel-aluminum bronze (NAB) is highly valued in applications where fatigue performance is crucial, such as marine propellers, pump components, and offshore structures, due to its exceptional mechanical properties and corrosion resistance. Considering the paramount importance of the fatigue performance of NAB, this study specifically explores the fatigue life of wire arc additive manufactured (WAAM) NAB under annealed conditions (675°C for 6 h, followed by furnace cooling). To this end, mechanical property assessment employing uniaxial tensile testing and depth-sensing nanoindentation testing and fatigue property assessment through load-controlled fully reversed fatigue testing was carried out at room temperature. Electron backscatter diffraction (EBSD) was utilized to understand the microstructure, texture, and grain size distribution of annealed WAAM NAB. Additionally, fatigue-fractured specimens were investigated through scanning electron microscopy-based fractography, and deformation behavior beneath the crack initiation zone was inspected through EBSD analysis. The results provide insights into the fatigue life, crack initiation, and propagation characteristics of WAAM NAB. The findings contribute to optimizing process parameters, designing fatigue-resistant components, determining accurate fatigue life, and ensuring the reliable utilization of WAAM NAB in critical applications.