Grain-boundary interfaces and void interactions in porous aggregates

A multiple-slip dislocation-density-based formulation and computational schemes that are coupled to grain-boundary (GB) interfacial schemes and an internal porosity formulation are used to analyse the behaviour and interaction of different arrangements and geometries of explicit pairs of voids in a polycrystalline fcc aggregate. The GB regions are treated as regions with properties and topologies that are distinct from that of the grain bulk. The GB kinematic scheme accounts for dislocation density interactions with GBs, such as dislocation density impedance, blockage and GB absorption. These evolving interfacial conditions are monitored throughout the deformation history. The analysis indicated that void-to-void interactions result in dislocation density evolution and saturation and porosity localization that are intricately related to both dislocation density pile-ups and blockages at GB interfaces, and GB absorption within different GB regions.