In-situ experimental investigation of the small fatigue crack behavior in CP-Ti: The influence of micronotch size

The influence of the micronotch size on the small fatigue-crack behavior of CP-Ti was investigated in this study. With an increase in the equivalent micronotch size, the fatigue life and average crack-arrest cycle decreased. Microstructural analysis revealed that crack arrest results from high-angle grain boundaries, and the post-arrest behavior is mainly characterized by the connection of main and secondary cracks, or the alternation of the slip system. A high crack propagation rate is correlated with prismatic slip. The activation of other slip modes may decrease the crack propagation rate. The micronotch size affected the distribution of the crack growth regions but had little influence on the long crack propagation rate.

Automated summary

The influence of micronotch size on small fatigue-crack behavior of CP-Ti was investigated. An increase in micronotch size led to a decrease in fatigue life and average crack-arrest cycle. Crack arrest was found to result from high-angle grain boundaries, and the post-arrest behavior was characterized by the connection of main and secondary cracks, or the alternation of the slip system. A higher crack propagation rate was associated with prismatic slip, while the activation of other slip modes could decrease the crack propagation rate. The micronotch size affected the distribution of crack growth regions, but had little influence on the long crack propagation rate.