In-situ SEM investigation and modeling of small crack growth behavior of additively manufactured titanium alloy

The fatigue crack growth of wire and arc additive manufactured Ti-6Al-4V alloys is investigated using in-situ SEM fatigue testing. The small crack initiation and propagation behaviors within grains and across grains are systematically studied, and the inter- and trans-granular crack growth rates are quantified. A synergy and competition among many factors such as persistent slip bands, grain boundaries, and crack branching governs the growth...