Study on corrosion fatigue of Ti-6Al-4V alloy under hydrostatic pressure environment in 3.5 % NaCl solution

This study examines the dual-phase Ti-6Al-4V alloy through corrosion fatigue tests in 3.5 wt% NaCl solution under different hydrostatic pressures. The effects of hydrostatic pressure and cyclic loading on the passive film, microstructure, and mechanical properties of the titanium alloy were investigated. Findings reveal that synergic effect of hydrostatic pressure and cyclic mechanical load reduces the compactness of the titanium alloy passive film, inducing crack initiation and propagation, accelerating the fatigue crack propagation rate , and reducing the fatigue life of titanium alloy. This study reveals the corrosion fatigue mechanism of titanium alloys under hydrostatic pressure and cyclic loading, providing reference values for designing components in deep-sea environments. • Hydrostatic pressure reduces the corrosion fatigue life of Ti-6Al-4V alloys. • Hydrostatic pressure interacts with cyclic loading deteriorating the passive film. • Hydrostatic pressure exacerbates stress on alloy surface under cyclic load.