APT as an “enabler” to better understand functional properties based on 3D-nanoscale information

Atom Probe Tomography is the most appropriate technique for 3D-nanometrology, i.e. the characterisation of both nanoscale structures (down to atom-size resolution) and their chemical composition in real 3D-space.

Atom Probe tomography (APT) is highly suitable to characterise e.g. precipitation behaviour or nano clustering and segregation of non-metallic alloying elements at grain or phase boundaries, essential in the development of new high-grade steels or metal alloys.

A dedicated lift-out sample preparation method, using our in-house Focused Ion Beam (FIB) for nano/micro-machining,   has been developed to prepare the needle-shaped specimens – “APT tips” – at the appropriate region of interest of the test material.

Atom Probe Tomography tip preparation with FIB; final tip radius < 10nm

The video below shows APT-analysis (iso-surfaces) of a maraging steel with smaller sphere shaped (red) and larger rod shaped (green) precipitates.

Hui SHI Maggie, Research Engineer Material Characterisation & Testing department, OCAS