Effect of hold time and environment on Fatigue Crack Growth Rate in Ti Alloys

In titanium alloys an effect of hold time at maximum load in a cyclic test is observed if K_max exceeds the threshold for crack propagation at a constant load test. For tests in air it is possible to predict crack growth rate for a hold time cycle from the crack growth rates from a cyclic test with triangular wave form and a constant load test. In 3.5% NaCl solution the measured crack growth rate is lower than the predicted.