The molecular dynamics method was used to simulate mode-I cracking in Ni3Al. Close attention was paid to the process of atomic configuration evolution of the cracks. The simulation results show that at low temperature, the Shockley partial dislocations were emitted before the initiation of the crack propagation, subsequently forming the pseudo-twins on (111) planes in crack-tip zone, and then the crack cleavage occurs. The emitting of the Shockley partial dislocations accompanies the crack cleavage during the simulation process. At the higher temperature, the blunting at the crack tip was caused by the [110] super-dislocations emitted on (100) plane. The present work also shows that the dipole dislocations on (111) planes in the 1/2[110] dislocation core could be formed.

Atomistic Simulation of Fracture in Ni3Al. Xie, H.X., Wang, C.Y., Yu, T.: Journal of Materials Research, 2008, 23[6], 1597-603