Relationship Between Grain Orientation and Crack Propagation Revealed by Phase-Field Crystal Simulation

The influence of different orientation angles on the microcrack propagation mechanism in nano twin crystal system under dynamic tensile conditions was investigated using the phase-field crystal method. The results show that under the same tensile conditions, the crack propagation mode, crack volume fraction, and crack propagation rate are related to the grain orientation. The difference in the crack propagation mechanism of the same orientation depends on the dislocation activity near the crack tip. A single dislocation located at the crack tip can easily lead to brittle expansion of the crack and accelerate the crack propagation rate. Dislocations in different directions at the crack tip may tangle together, which in turn hinders the crack propagation.