The effect of Fe solute atom on interface structure and deformation behavior of Cu/FexNi1-x layered composites by molecular dynamics

Abstract

Molecular dynamics investigated the effect of Fe solute atom on interface structure and deformation behavior of Cu/FexNi1-x layered composites. Ultimate stress first increases, then decreases, and then increases again with the increase of Fe content. When Fe content is between 20 % and 30 %, ultimate stress reaches the maximum value, which is 15.2 % higher than that of Cu/Ni. As the Fe content increases, stress concentration region on interface shifts from Cu layer to FexNi1-x layer, then to Cu layer, initial dislocation nucleation source on interface transfers from triangular node on Cu side to misfit dislocation line on FexNi1-x side, then to strip region on Cu side, and plastic deformation mechanism of FexNi1-x layer changes from slip of leading and trailing dislocations to slip of partial dislocations, then to slip of perfect dislocations. When Fe content is low, dislocation density rapidly increases to its peak, then decreases, and finally fluctuates around certain value, especially in the Fe30Ni70 layer where the dislocation density decreases to very low value, and interface morphology presents wavy. However, when Fe content is high, dislocation density slowly increases to its peak and then fluctuates around the peak, and interface morphology presents flat. Shear strain width of interface region decreases as Fe content increases, which indicates the interface of Cu/FexNi1-x with low Fe content has good plastic harmonized deformation ability.