Investigation of the dwell period's influence on the fatigue crack growth of a titanium alloy

The dwell effect, which is known to induce a reduction in the fatigue life of titanium alloys at room temperature, is related to early crack initiation. The present results support faster crack growth rates. The governing mechanisms are identified by mean of scanning electron microfractographic observations. The potential role of the atmosphere is examined through comparative testing performed in air and in high vacuum in order to distinguish the specific contributions of cold creep and environment assistance. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.