Influence of interface on deformation compatibility of a heterogeneous Cu/Al nanoscale multilayer

Abstract

The incompatible deformation among the constituent layers usually results in extremely low tensile ductility in nanoscale metallic multilayers. Here, molecular dynamics simulations are conducted to investigate the deformation compatibility of a heterogeneous Cu/Al multilayer with various interface structures under compression. The results show that, by selecting an appropriate thickness of thin interlayers, the heterogeneous Cu/Al nanolayered composite with (1¯1¯1) interface exhibits excellent compatible deformation between the soft and hard layers while the homogeneous counterpart does not. The excellent deformation compatibility of the heterogeneous structure originates from the presence of the thin soft interlayer that can enhance the dislocation activities of the hard layers. Unlike that with (1¯1¯1) interface, the heterogeneous structure with (001) interface shows obvious incompatible deformation among the component layers. Such a scenario can be attributed to the stable dislocation network on the (001) interface, making the dislocations in the soft phase difficult to cross the interface into the hard phase. These findings may deepen our understanding of the deformation compatibility of heterogeneous nanoscale metallic multilayers.