Characterizing solute hydrogen and hydrides in pure and alloyed titanium at the atomic scale

Ti has a high affinity for hydrogen and are typical hydride formers . Ti -hydride are brittle phases which probably cause premature failure of Ti -alloys. Here, we used atom probe tomography and electron microscopy to investigate the hydrogen di stribution in a set of specimens of commercially pure Ti , model and commercial Ti -alloys. Although likely partly introduced during specimen preparation with the focused- ion beam, we show formation of Ti-hydrides along α grain boundaries and α / β phase boundaries in commercial pure Ti and α + β binary model alloys . No hydrides are observed in the α phase in alloys with Al addition or quenched-in Mo supersaturation

Interfaces and defect composition at the near-atomic scale through atom probe tomography investigations

Atom probe tomography (APT) is rising in influence across many parts of materials science and engineering thanks to its unique combination of highly sensitive composition measurement and three-dimensional microstructural characterization. In this invited article, we have selected a few recent applications that showcase the unique capacity of APT to measure the local composition at structural defects. Whether we consider dislocations, stacking faults, or grain boundary, the detailed compositional measurements tend to indicate specific partitioning behaviors for the different solutes in both complex engineering and model alloys we investigated