Interaction of dislocations and cracks in grains based on discrete dislocations

A interaction model between discrete dislocation emission and the grain boundary at the crack tip of microscale grain is described. When the dislocation emission condition is satisfied, dislocations will be emitted from the crack tip and will move along a slip plane to the grain boundary. Dislocations will pile at the grain boundary and create stress concentration. At this time dislocation penetration and crack nucleation at the grain boundary may occur. The distribution and penetration of dislocations at the crack tip will have a new effect on the crack. In this paper, different grain boundary angles and grain sizes are studied to find the relationship between dislocations and cracks. The results show that the main crack tends to propagate in large grain boundary angle and in small grain size crystalline materials. And wedge crack in the grain boundary tends to initiate with large grain boundary angle and in large grain size crystalline materials.

Automated summary

This paper describes the interaction model between discrete dislocation emission and the grain boundary at the crack tip of microscale grain. The distribution and penetration of dislocations have a new effect on the crack. The results show that the main crack tends to propagate in large grain boundary angle and in small grain size crystalline materials, while wedge crack in the grain boundary tends to initiate with large grain boundary angle and in large grain size crystalline materials.