Anisotropy effect on the motion of edge dislocation in body-centered-cubic Fe

The mechanical properties of metallic materials can be dictated by nucleation, multiplication, and motion of dislocations under stress. We employed the molecular dynamics (MD) method to investigate the motion of an 1/2[111](112̄) edge dislocation in body-centered-cubic (BCC) Fe under normal stress on the 112̄ plane. Our MD results confirm that the motion of the edge dislocation can be attributed to the normal stress induced shear stress (NSISS) effect. The magnitude of this effect varies across different cubic metals. Further studies reveal that this effect is limited to the {112} planes and is associated with the disobedience of Schmid’s law in the case of twinning of BCC Fe. To summarize, the NSISS effect may be traced back to the anisotropy of cubic metals and should be considered when the twinning process in anisotropic BCC metals is studied.