Apr 9, 12:00 - 13:00 (ET)
Thermal Alleviation Effects on the Dwell Fatigue Life of Ti-6Al-4V
Speakers: Joel Davis, Rolls-Royce Date: Thursday, April 9, 2026 Time: 12:00 pm Duration: approximately 30 minutes; questions and answers to follow Registration: https://cummins.zoom.us/meeting/register/AjuW6jHqR-qXzYyKEnfbKg
Abstract: Cold dwell fatigue is a failure mechanism present in titanium alloys that stems from creep at low temperatures in grains well oriented for crystallographic slip. Dwell fatigue is a temperature dependent phenomenon and at elevated temperatures no reduction in fatigue life is observed. Material exposed to elevated temperatures in this range for a portion of its loading cycle do not exhibit a reduction in fatigue life, due to a thermal alleviation (TA) process that has not been previously studied in the open literature. In this research project, the effect of TA on the dwell fatigue properties of Ti-6Al-4V (Ti-64) will be investigated. Each fatigue specimen was exposed to a single mid-life TA event which increased the fatigue life of the specimen when compared to specimens without such treatment. TA was found to temporarily reduce the rate of plastic strain accumulation in the test specimens during the dwell periods. The number of cycles for reduced plastic strain accumulation, representing the TA effect, was found to decrease as applied stress increased and as temperature decreased. Measurement of intragranular misorientation using EBSD, as a proxy for geometrically necessary dislocation content, demonstrated a reduction in dislocation density for temperatures corresponding to large reductions in the rate of plastic strain accumulation. At temperatures near the critical TA temperature a change in intragranular misorientation was not detected with TA. It is therefore likely that the mechanistic basis for TA is due to an evolution of the dislocation structure in response to time at elevated temperature
About the speakers: Joel Davis is a materials engineer at Rolls-Royce Corporation in Indianapolis IN working in materials testing and data analysis. He recently completed a master’s degree in materials engineering from Purdue University. His thesis work was on the thermal alleviation of dwell fatigue in Ti-6Al-4V.