Atomic structure, tensile property, and dislocation behavior of Fe–W interfaces from molecular dynamics simulation

Abstract

Molecular dynamic simulations based on a recently constructed potential reveal that quasi-repeating patterns could appear in both Fe(110)/W(110) and W(110)/Fe(110) interfaces, and that three kinds of atomic displacements of Fe atoms because of the Fe–W interaction intrinsically bring about the interesting quasi-repeating patterns of the Fe–W interfaces. It is also found that the Fe–W interface becomes more brittle with less critical strains under tensile loading than pure Fe or W, which is fundamentally attributed to the movement of the interface dislocations as a result of the lattice mismatch between Fe and W. Interestingly, the dislocation loops could be formed in the Fe–W interface under tensile loading due to the pinning of the 100 edge dislocations by the edge dislocations of 1 / 2 111 , whereas no dislocation loop would be generated in pure Fe or W.

Molecular dynamics simulations of tensile mechanical properties and microstructures of Al-4.5Cu alloy: the role of temperature and strain rate

“…When the strain rate is 1 × 10 10 s −1 , the dislocation nucleation stress gradually decreasing with the increasing of temperature, and the variation range of nucleation stress gradually increasing at the same time, as shown figures 2(b) and (e). This illustrates Al-4.5Cu alloy obviously appear plastic deformation rather than only elastic deformation during high temperature tensile [40]. And the degree of plastic deformation becomes more and more obvious as the temperature goes up.…”