Observation of morphology and stress distribution around dislocation in Ni3Al on the atomic scale

Dislocation is very important for the properties of materials. In this work, morphology and stress distribution around dislocation in Ni3Al are observed in atomic scale by the molecular dynamics. We obtained the dislocation morphology by the simulation and found that the atom distribution around the dislocation core is irregular. Layers of atoms on both the left and right sides of the dislocation core leans to the core, and about six layers of atoms are fractured due to the missing of the half plane of atoms. Along the [1 1 1] direction, there are about eight layers of atoms deviating from its equilibrium position. These results demonstrated that influenced area of dislocation is pipe-like. The stress distribution agrees with the results from the formula. Both normal stress and shear stress components exist in the edge dislocation stress field, normal stress mainly concentrating on two sides of the dislocation line, while the shear stress exist several angstrom away from the dislocation line.