Molecular Dynamics Study of Defect Evolutions and Mechanical Properties of W/Fe Semi-Coherent Interfaces under Irradiation

Molecular dynamic simulation has been performed to systematically investigate defect evolutions and mechanical properties of W/Fe semi-coherent interfaces under irradiation. For the simulation of damage cascades, a recently published EAM potential by our group has been first corrected using the universal potential of ZBL. On this basis, the dislocation loop evolutions and stress-strain curves of the irradiated W(110)/Fe(110) and W(100)/Fe(100) semi-coherent interfaces are derived. It has been found that interstitial atoms of pure W and Fe seriously accumulate with the increasing of irradiation times. Surprisingly, the formation of semi-coherent interfaces can trap the interstitials, and consequently inhibit the dislocation loop nucleation in W and Fe bulks to improve the irradiation resistance. The fundamental effects of interface orientation are also disscussed, and give a deep understanding of mechanical properties of W/Fe interfaces under irradiation.