Grain Boundary-Dislocation Interaction Simulations Designed to Allow Transmission

The advance of experimental and simulation tools have advanced our ability to examine grain boundary (GB)-dislocation interactions in greater numbers and detail. These interactions underpin the well-known Hall-Petch relationship, which still lacks understanding of just how each individual GB-dislocation interaction contributes to the overall material response. Predicting the types of GB-dislocation interactions that can occur remains a challenge because the conditions for each can be so complex and unique. We designed a specific set of simulations to address these challenges and account for the variability that is inherent in these types of interactions. The simulations are limited to [112] tilt boundaries in FCC Ni, such that slip plane and slip direction alignment are maximized for transmission. Additionally, it is well-known that GBs can assume different atomic configurations, so we examined 3 different atomic structures for each GB. We present the results of these simulations and the corresponding GB-dislocation interactions. Interestingly, despite the attempts to maximize transmission in these simulations, only 4 of the 27 simulations show direct transmission. Another 5 simulations have dislocation nucleation at another site, somewhat removed from the site of impact. The remaining simulations demonstrate absorption of the dislocation with no indications of transmission or nucleation of any kind. These results are discussed in the context of the literature and the impact it could have on how we may wish to consider GB-dislocation interactions in general.