[SY-C3] Symposium C-3

[SY-C3] Quantifying the effect of hydrogen on dislocation dynamics in microcrystals: A three-dimensional discrete dislocation dynamics study

Invited

Yejun Gu, ^○Jaafar A. El-Awady (Johns Hopkins University, United States of America)

We present a new framework to quantify the effect of hydrogen on dislocation plasticity using large scale three-dimensional (3D) discrete dislocation dynamics (DDD) simulations. In this model, the first order elastic interaction energy associated with the hydrogen-induced volume change is accounted for. The three-dimensional stress tensor induced by hydrogen concentration, which is in equilibrium with respect to the dislocation stress field, is derived using the Eshelby inclusion model, while the hydrogen bulk diffusion is treated as a continuum process. This newly developed framework is utilized to quantify the effect of hydrogen on the different aspects of dislocation-mediated plasticity in Ni single crystal microcrystals. The combined effect of hydrogen concentration, crystal size, and dislocation density is quantified. Finally, the effects of pipe diffusion is also rationalized from comparisons with experimental results.