Fatigue crack growth behavior of titanium with oxygen impurities: Experiments and modeling

The long-term reliability of structural elements in many advanced applications, such as power generation and transportation infrastructures, is paramount, especially under cyclic damage conditions. In this work, fatigue crack growth experiments were performed in commercial purity titanium with different initial oxygen contents and load ratios (R). To model fatigue crack initiation and growth, a fatigue indicator parameter (FIP) along with high-resolution crystal plasticity simulations were carried out. The crack-nucleation along with microstructurally short crack (MSC) growth models are calibrated for R = 0.1 with different oxygen contents. The resulting calibrated parameters along with the average total FIP values for R = 0.2 were used to predict nucleation and MSC growth behavior. Results indicate that this approach can predict the number of cycles required for crack nucleation and MSC behavior.