A Frank scheme of determining the Burgers vectors of dislocations in a FCC crystal

Abstract

A Frank scheme based on the Thompson’s tetrahedron is developed to calculate the Burgers vector of dislocations in a face-centered cubic (FCC) crystal during its plastic deformation. A Burgers circuit is located firstly in a deformed crystal with a reference circle surrounding one or more dislocations. The atom-to-atom sequence in a dislocation-free crystal corresponding to the Burgers circuit is determined not from a local reference lattice, but from the edge vectors of the Thompson’s tetrahedron and its mirrors. The final Burgers vector obtained by its Frank definition is accurate, regardless of the position, size and normal direction of the initial reference circle, as long as the same dislocations are surrounded. The present method is validated in determining the Burgers vectors for the dissociation of a perfect dislocation and for the complex reactions of the dislocations from a nanovoid in a deformed crystal under a uniaxial tensile loading.