Multiscale modelling of bi-crystal grain boundaries in bcc iron

Atomistic simulations have provided much insight into grain boundary (GB) structures and mechanisms which are important in understanding the properties of materials. In this paper, the ∑3{1 1 2}, ∑3{1 1 1} and ∑5{0 1 3} (coincidence site lattice) GBs of bcc iron are investigated using molecular statics (MS) simulations, ab initio DFT calculations and the simulated HRTEM method. For the MS calculations, four empirical potentials, the Ackland potential (1997), Mendelev potentials 2 and 4 and the Dudarev–Derlet potential have been used. The MS results for all three symmetrical grain boundaries show the results to be independent of the empirical potential implemented. After relaxation, the symmetrical structures of the GBs remain, in agreement with ab initio calculation results.