Fatigue crack propagation in titanium alloys with lamellar and bi-lamellar microstructures

This paper focuses on the fatigue crack propagation behavior of bi-lamellar titanium microstructures in comparison with conventional lamellar microstructures. While the bi-lamellar condition showed a higher resistance to microcrack propagation, the differences in macro-crack propagation behavior of the lamellar and the bi-lamellar condition were found to be relatively small as a result of the superposition of counteracting contributions. In vacuum tests, the influence of test temperature is quite small for both microstructures. The effect of environment (air) increases strongly with temperature; the bi-lamellar condition being somewhat less affected than the lamellar condition.