Atomistic simulations of interaction of edge dislocation with twist grain boundaries in Al-effect of temperature and boundary misorientation

Interaction of run-in edge dislocations with twist grain boundaries in Al-a molecular dynamics study

“…In order to facilitate the application of shear force during MD simulation, free surfaces were created along the y-direction. Special orientations of grain 2 were chosen to minimise the lattice mismatch between the two grains [19]. The length of the simulation cell along y-and z-directions was chosen such that it maintains the periodicity along these directions.…”

“…For further details on the GB configuration and geometry, see Ref. [19]. In this work, we advance our study to identify the various aspects of interaction of multiple dislocations with GBs and also to gain further insights into the underlying mechanisms during deformation.…”

“…These interactions include (a) nucleation and emission of lattice dislocations from the GB [7,12,13], (b) slip transmission across the boundary [14][15][16], (c) dislocation reflection from the GBs [17,18], etc. Over the last decade, investigations of dislocation-GB interactions have gained increased attention by means of molecular dynamics (MD) simulations, both in bicrystals [19][20][21][22][23][24][25] and in bulk 3D nanocrystalline samples [26][27][28][29]. However, only a few number of studies in the literature have focused on slip activity due to dislocation pile-ups and a limited research has been devoted in this regard.…”

“…This information has to be gleaned from atomistic level calculations, as continuum level approaches are not able to explicitly capture the dislocation-GB interactions. MD simulations on bicrystals, although, have already proven their utility in this regard [14,19,33,41], but only for a single isolated dislocation. This may not be able to capture the phenomena involving interaction of multiple dislocations with GBs.…”

“…Al is considered to study the complex interplay of various dislocation processes triggered by the stress concentration due to a pile-up of edge dislocations with various <1 1 0> twist GBs. We had earlier simulated a single absorption event of an edge dislocation in Al bicrystal, and quantified the absorption resistance for twist GBs of various misorientation angles [19]. For further details on the GB configuration and geometry, see Ref.…”