Abstract
Molecular dynamics simulation is performed on α-iron having two kinds of lattice orientations including the primary slip direction of [111] for bcc crystal. The crack on the (100) plane with crack tip direction [011] and that on the (011) plane with crack tip direction [011] are studied. For the crack on the (100) plane with its tip direction [011], no dislocation emission is observed, and the crack propagates on the (100) plane in both low-and high-temperature environments. For the crack on the (011) plane with its tip direction [011], brittle fracture without dislocation emission occurs at low temperature, but at high temperature [111] dislocation emission from crack tip is observed. The local stress on the cleavage plane and the slip plane is discussed from the viewpoint of fracture mechanism.
