Effect of nitrogen content on the crack growth behavior in the Fe-N alloy at high temperatures via molecular dynamics simulations

In this work, the influence of nitrogen content on the crack propagation behavior in Iron-Nitrogen (Fe-N) nano crystalline was studied at high temperatures using molecular dynamics (MD). The semi-empirical Modified Embedded Atom Method (MEAM) potential function was utilized to model the interatomic interactions. The results revealed that at higher temperature of 900 K and 1100 K, more slip systems are activated resulting in the crack tip blunting ahead of crack tip and void nucleation and growth. Moreover, the results showed that the deformation mechanism and fracture behavior are significantly altered owing to the initial nitrogen concentration. The simulated results indicated the slow crack propagation at low nitrogen content of 0.1 wt.%. Detailed analysis confirmed that nitrogen concentration has a significant effect on the crack propagation. At high nitrogen content (0.51 wt.%), the crack growth increased by changing the crack propagation path.