|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Fatigue in Materials: Fundamentals, Multiscale Modeling and Prevention
||Fatigue in Titanium: Dislocation Mechanisms, Initiation, Hydrogen and Alpha2
||David Dye, Trevor Lindley, Tamara P Chapman, Anna Radecka, Edward A Saunders, Paul A Bagot, Adrian R Walker, Thomas Martin, David Rugg
|On-Site Speaker (Planned)
Alpha-Ti can be vulnerable to some unusual cracking modes. In low cycle fatigue Ti3Al precipitation (alpha2), aka short range ordering, is strongly implicated in the vulnerability of high-Al alloys to dwell fatigue at near-ambient temperatures. This gives rise to characteristic dislocation structures and consequent slip localisation. These will be related to the Stroh model. However, the formation mechanism, compositions of the alpha2 and precipitation kinetics have remained difficult to study. Recent progress in atom probe tomography has allowed these Al-rich clusters to now be imaged and these results will be shown. IMI834, Ti-64 and Ti-7Al will be compared; surprisingly beta stabilisers appears to accelerate alpha2 formation. At the same time, similar dislocation structures are observed in hydrogen-embrittled hot salt stress corrosion cracking (HSSCC); dislocations from a real HSSCC crack will be shown and some thoughts on the links between dwell and HSSCC discussed.
||Planned: Publication Outside of TMS (Indicate publication title and publisher if known.)