Effects of void–crack interaction and void distribution on crack propagation in single crystal silicon

•The existence of a void ahead of crack tip can retard crack propagation speed.•For two-parallel-void model, crack propagation tends to be blocked by voids coalescence.•For two-perpendicular-void model, crack blunting in the ligament can block crack propagation.•Different blocking effects can be explained by the geometry modification of crack process zone.

Interaction between crack and pre-existing voids in single crystal silicon has been investigated by performing molecular dynamics simulation. It is found that the presence of a single void, ahead of crack tip, can affect the crack propagation through crack–void interaction in one-void model. As the crack–void ligament distance gradually approaches the critical distance, the crack propagation speed decreases. For two-void model, crack propagation behaviors can be substantially influenced by voids distributions (voids aligned along or perpendicular to crack line) under different crack retarding mechanisms, indicating that the distribution of voids provides a prominent role in blocking the crack propagation.