Predicting dwell fatigue life in titanium alloys using modelling and experiment.

ABSTRACT: Fatigue is a difficult multi-scale modelling problem nucleating from localised plasticity at the scale of dislocations and microstructure with significant engineering safety implications. Cold dwell fatigue is a phenomenon in titanium where stress holds at moderate temperatures lead to substantial reductions in cyclic life, and has been implicated in service failures. Using discrete dislocation plasticity modelling complemented by transmission electron microscopy, we successfully predict lifetimes for 'worst case' microstructures representative of jet engine spin tests. Fatigue loading above a threshold stress is found to produce slip in soft grains, leading to strong dislocation pile-ups at boundaries with hard grains. Pile-up stresses generated are high enough to nucleate hard grain basa

SUBMITTER: Xu Y 

PROVIDER: S-EPMC7672227 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature