Evaluation of Fatigue Crack Growth in α-Titanium Alloys

The fatigue crack growth modeling that based on linear fracture mechanics under the Mode I condition provided a good estimate of the stress intensity range for subsurface crack growth in α or near α-type titanium alloys. Based on the relationship between crack growth rate and stress intensity factor range, the fatigue crack propagating life was evaluated by the Paris rule. The subsurface crack initiation process consumed a large number of cycles to failure. Microstructure may strongly affect on not only subsurface crack initiation but also crack growth. The microstructural modification to prevent microcrack growth should be taken into account.