|About this Abstract
||2014 TMS Annual Meeting & Exhibition
||Multiscale Approaches to Hydrogen-assisted Degradation of Metals
||On the Implication of Dislocations and Vacancies Distributions on Hydrogen Diffusion and Trapping in FCC Alloys: Grain-boundaries and Dislocation Patterns
||Xavier Feaugas, Abdelali Oudriss, Arnaud Metsue, Catherine Savall, Jamaa Bouhattate, Juan Creus
|On-Site Speaker (Planned)
The impact of dislocation distribution on hydrogen diffusion and trapping mechanisms have been investigated in nickel for a large range of grain sizes and strengthened (100) single crystals. The high-angle Random boundaries (R) are considered as a desordered phase where the hydrogen diffusion is accelerated, while the Special boundaries (CSL) constitute a potential zone for hydrogen trapping due to the high density of trapping sites as dislocations and vacancies. For the dislocation walls issued from the plastic deformation, the hydrogen mobilty depends on the type of loading imposed on the samples : fatigue or tensiles tests. It is shown that incidental dislocations boundaries (IDB) obtained by tensile loading lead to a trapping process. In opposition, the dipolar structure and vacancies formation during cyclic loading seem to promote hydrogen diffusion. For each cases hydrogen increases the vacancies concentration in a similar way as we reported for GBs.
||Planned: Paper Selections