| Abstract Scope |
Revealing Hydrogen-defect interactions provides insights on significant ductility loss due to the particular strain partitioning in H-charged structural alloys. Experimental investigation of these interactions are extremely difficult, labor intensive, and costly. This limitation motivates the development of simulation models to study nanoscale interactions. Using hybridization and parallelization of molecular dynamics and grand canonical Monte Carlo, polycrystalline scale atomistic models of H-diffusion deformation can be simulated with high efficiency. To study H-grain boundary interactions at various concentrations, we developed a model containing 8 randomly oriented grains and studied the characteristics of H segregated sites with respect to H-free ones. We analyzed the dislocation activities, e.g., dislocation type, length, distribution of grain boundaries in two scenarios. To study H-crack surface interactions, large pillars including all possible sites from different angles of free-surfaces were modeled. We will discuss how H significantly changes dislocation activities of these defects leading to the ductility loss. |