Hydrogen-induced embrittlement of group IVB transition metals
||Hydrogen-induced embrittlement of group IVB transition metals|
||SNIC Medium Compute|
||Jakob Blomqvist <email@example.com>|
||2022-06-27 – 2023-07-01|
The purpose of the present project is to investigate the impact of hydrogen on the mechanical properties of group IVB transition metals (e.g. zirconium (Zr) and Titanium (Ti)) by means of large-scale atomistic modelling.
There are two main objectives. First we aim to model the impact of hydrides and hydrogen solute clusters on the mobility of dislocations, to predict the increased drag and its influence on the plastic properties and hardening. The data from these simulations will be used as input to parametrize the analytical Friedel Kroupa Hirsch (FKH) and Bacon Kocks Scattergood (BKS) models to describe the critical (i.e. Peierls) stress required to enable dislocation glide past the obstacles. This information will be used in Discrete Dislocation Dynamics simulations to quantify the hardening on a microscopic length scale. To this end we will need to fit new empirical interatomic potentials for the Zr-H and Ti-H systems, which will be trained using DFT data generated herein.
For the second objective, we aim to use DFT modelling to identify preferential glide systems in metastable hydrides. Particularly the recently discovered gamma and zeta hydrides are of great interest since their impact on the plastic behaviour is unknown. For these phases it is further of interest to investigate how the elastic properties vary with temperature. They will be modelled by means of DFT, through the usage of the quasi-harmonic approximation.