Deformation mode transitions in Cu₅₀Zr₅₀ amorphous/Cu crystalline nanomultilayer: A molecular dynamics study

The amorphous/crystalline (A/C) nanomultilayers have been aroused great interest in people due to its first-class mechanical properties. The effects of the thickness of crystalline and amorphous on the deformation mechanism of A/C CuZr/Cu nanomultilayers under tension loading here are investigated by molecular dynamics method. The results indicate that the mechanical behavior of nanomultilayer strongly depends on the bidirectional synergistic deformation mechanism between crystal phase and amorphous phase. The deformation behavior of nanomultilayers can be controlled by integrating the thickness of different phases to achieve high strength and superplastic multilayer materials. For the nanomultilayers with constant crystal layer, the plastic deformation changes from shear band propagation to a pronounced interface slip-accommodation mechanism, and ultimately to crack propagation mode with decreasing amorphous thickness. For the nanomultilayers with fixed amorphous layer thickness, the mechanical behavior changes from localization to plastic co-deformation mode with the crystalline thickness decreases. This study proposes an approach for achieving a good balance between strength and ductility, which is useful for the synthesis of A/C nanomultilayer with high strength and predominant ductility.