Cohesive laws describing the interface behaviour of iron/precipitate interfaces under mixed loading conditions

The behaviour of 11 differently oriented iron-precipitate interfaces under mixed loading conditions is studied with molecular dynamics simulations. We find that the interface structure and the change in this structure play a key role in the response to the loading. The structure change is influenced by both the loading history and the loading direction. Depending on the interface and the loading direction, the presence of a dislocation at the interface may have an additional influence on the structure change. We update our previously derived cohesive laws for pure shear and pure tensile loading to take into account the influence of the other loading direction on the behaviour during mixed loading conditions. However, not for every interface a unique relation exists between the separations at the interface and the tractions. In those cases our cohesive laws give no exact prediction, but rather a range of possible values. The cohesive laws are intended to be used in numerical methods at the next larger length scale, such as discrete dislocation plasticity.