Atomic simulation of mechanical properties of single crystal tungsten after self-irradiation

The mechanical properties of single crystal (SC) tungsten after self-irradiation were studied under different irradiation directions and energies using molecular dynamics (MD) method at room temperature. First, one primary knocked-on atom (PKA) was selected inside the SC tungsten, and then different energies (5, 10, 15 and 20[Formula: see text]KeV) were applied to the [111], [122] and [135] directions, respectively, to simulate the self-irradiation effect. Finally, the obtained self-irradiation models were uniaxially stretched to study the mechanical properties of SC tungsten after self-irradiation. The results showed that the yield stress and yield strain gradually decreased with the increase of self-irradiation energies in [111] direction, and the elastic modulus gradually increased. For the [122] direction, the yield stress and yield strain first increased and then decreased, but the elastic modulus first decreased and then increased. However, in [135] direction, the mechanical parameters showed a fluctuating trend and the regularity was not obvious. And it was also found that the deformation mechanisms of SC tungsten after self-irradiation were slip bands, dislocation rings, clusters and damage accumulation, but the distribution of deformation mechanisms was different under different irradiation directions and irradiation energies, which directly affected irradiation mechanical properties of SC tungsten.