Atomic-scale simulations of the interaction between dislocations and tilt grain boundaries in α-iron

Abstract

The interaction of lattice dislocations with symmetric and asymmetric tilt grain boundaries has been simulated for different grain boundary misorientation angles by means of the molecular dynamics method using embedded atom method (EAM) potentials. An edge dislocation is equidistantly placed between a grain boundary and a free surface. The movement of the dislocation occurs during relaxation in the absence of external stress and is a result of competitive attractions from the grain boundary and the free surface. The evolution of the position of the dislocation is analysed. An attraction force from the grain boundary has been found in all cases. The strongest attraction has been observed for the cases when the glide plane of the dislocation is perpendicular to the grain boundary. A similar effect has been found for low and room temperatures. An analysis of microscopic stresses has also been performed. © 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.