|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Interface-driven Phenomena in Solids: Thermodynamics, Kinetics and Chemistry
||Atomic Investigation of the Role of Alloying Elements on the Thermodynamics of Vacancies and Vacancy-Hydrogen Clusters at Symmetric Tilt Boundaries in Nickel
||Xiao Zhou, Jun Song
|On-Site Speaker (Planned)
Hydrogen embrittlement (HE) has sparked off great scientific attention.Despite much work on HE, investigations on the role of alloying elements on HE are largely absent. In this study, we examined several common alloying elements (Cr, Mo, Nb, Al and Ti) and their influences on the formation and segregation of single vacancies (SVs) and vacancy-hydrogen clusters (VHxs) at several symmetric tilt grain boundaries (STGBs) in Ni. Significant reduction of formation energies of SVs and VHxs can be realized by the presence of some alloying elements. This reduction was found to be correlated with the solute-induced local lattice distortion. Our results show that the alloying elements can potentially contribute to the local segregation of vacancies to promote the formation of micro-voids or micro-cracks, even along otherwise HE-resistant coherent boundaries in certain Ni-based alloys under hydrogen charging, providing a new perspective towards the understanding of HE in Ni alloys.
||Planned: A print-only volume