抄録
Crack propagation in Magnesium is investigated using molecular dynamics simulations. By providing atoms in a disk-shaped simulation cell with the displacement evaluated by the anisotropic elastic theory, propagation of a crack is carried out. For an embedded atom method (EAM) potential, basal and first-pyramidal surfaces are favorable cleavage planes due to relatively low surface energies. MD simulations using EAM show brittle fracture behavior with basal or first-pyramidal cleavage surface. On the other hand, a generalized embedded atom method (GEAM) potential, the basal plane has larger critical stress intensity factor by the Griffith's formula. Consequently, in GEAM simulations of crack propagation, ductile fracture occurs as dislocations and deformation twins are generated in the vicinity of the crack front.
