The role of oxygen in Ti-alloys for aerospace

Titanium-alloys are the dominant engineering material in modern aircraft frames, internal structures and gas-turbine engines due to their unsurpassed characteristics of excellent corrosion resistance and high specific strength. A current area of interest in these alloys is the role of oxygen, which strengthens but also cause embrittlement. The exact mechanism by which oxygen does this, along with how it varies in different alloys is not properly understood.

In this project, carried out in close collaboration with Rolls-Royce plc, the advanced characterisation tool of Atom Probe Tomography (APT) will be utilized to study a range of commercial alloys with different introduced oxygen contents, aiming to explore where oxygen resides with the microstructure, whether at dislocations, grain boundaries or phase interfaces, and how this may change with heat treatments. Supporting Transmission/Scanning Electron Microscopy experiments and mechanical testing will also be carried out to properly link atomic-scale chemistries to engineering performance. A second theme will be exploring the structure of oxides and oxygen-rich layers formed at the surface of components exposed to working environments, along with developing and utilising unique reaction cell facilities within the Atom Probe Tomography group to carry out tightly controlled realistic exposures.

EPSRC Theme: Engineering