Intermixing of chemical species as a result of interdiffusion during processing leads to the development of diffuse interface structures which have distinct properties compared to the atomically sharp interface.
The effect of interdiffusion on interface properties is complex due to the opposing effects of interdiffusion induced changes to the interface structure, namely the presence of solute atoms and a reduced misfit dislocation density, on the interface shear strength.
Representative {111} Cu/Ni interfaces with different levels of interdiffusion are generated and subjected to shear loading using atomistic methods to study the effects of these interface structure changes on the interface response to shear.
It is found that interdiffused models exhibit improved interface shear strength relative to the atomically sharp case; however, shear strength does not increase monotonically with solute concentration.
The distribution of maximum changes in energy per misfit node, as filtered using microrotation vector analysis, suggest heterogeneous interface resistance to sliding, also confirmed by non-uniform misfit node displacements.
The number of solute atoms near misfit node centroids does not correlate well with misfit node displacements indicating the importance of the longer-range misfit dislocation structure.
Increased activation of misfit dislocation glide is associated with larger solute concentrations as a result of the larger misfit node displacements.
Change in energy analysis, however, reveals that misfit dislocations do not contribute significantly to the interface resistance to sliding and interface sliding is instead dominated by the misfit node behavior.
These results highlight the importance of modeling more realistic diffuse interface structures and motivate additional studies into the competing effects of solute content and misfit density.
