|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Advances in Titanium Technology
||Towards Sub-nanometer Scale Characterizing the ‘Real’ H in Titanium Alloy - Importance of Combined Cryogenic Focused Ion Beam & Atom Probe Tomography Technique
||Yanhong Chang, Wenjun Lu, Abigail Ackerman, David Dye, Dirk Ponge, Dierk Raabe, Baptiste Gault
|On-Site Speaker (Planned)
Atom probe tomography (APT) enables to characterize and visualize the 3D distribution of H at sub-nanometer scale within engineering materials. For Ti-alloys, cryogenic focused-ion beam (cryo-FIB) is proved to eﬃciently inhibit the introduction of H from the environment during specimen preparation, meanwhile, prevent out-diﬀusion of preexisting H/D previously charged into the material. By using cryo-FIB for sample preparation and semi-correlative STEM-EELS/APT for structural/chemical characterization, the controversial face-centered-cubic phase in electro-polished thin foils of cold-rolled commercially pure Ti was unambiguously identiﬁed as Ti hydride, instead of a new allotrope of Ti. The inﬂuence of D pre-charging on the chemistry and phase composition of the commercial alloy Ti6246 was investigated by using combined cryo-FIB&APT techniques. The results imply that the experimental parameters, such as H fugacity, charging temperature, etc., need to be carefully selected when aiming to study the hydrogen embrittlement behavior of Ti-alloys in services.
||Titanium, Characterization, Other