An approach was introduced in which the results of atomistic simulations were combined with discrete dislocation dynamics simulations of crack-tip plasticity. The method was used to study the effects of dislocation pinning, due to grain boundaries or secondary particles, on the fracture behavior of Al. It was found that the fracture resistance decreased with decreasing pinning distance. The results showed that pinning of the dislocations caused a net decrease in the shear stress on the slip plane; thus preventing further dislocation emission. Semi-brittle cleavage occurred when a certain number of dislocations had been emitted.

Dislocation Pinning Effects on Fracture Behavior - Atomistic and Dislocation Dynamics Simulations. S.J.Noronha D.Farkas: Physical Review B, 2002, 66[13], 132103 (4pp)