Atomistic survey of grain boundary-dislocation interactions in FCC nickel

It is well known that grain boundaries (GBs) have a strong influence on mechanical properties of polycrystalline materials. Not as well-known is how different GBs interact with dislocations to influence dislocation movement. This work presents a molecular dynamics study of 33 different FCC Ni bicrystals, each subjected to four different loading conditions to induce incident dislocation-GB interactions in 132 unique configurations. The resulting simulations produce 189 dislocation-GB interactions. Each interaction is analyzed to determine properties that affect the likelihood of transmission, reflection, or absorption of the dislocation at the GB of interest. The results confirm the ability to predict the slip system of a transmitted dislocation using common geometric criteria. Furthermore, machine learning reveals that geometric properties, such as the minimum residual Burgers vector (RBV) and the disorientation angle between the two grains, are strong indicators of whether or not a dislocation will transmit through a GB.