Uniaxial tension deformation study of copper/nickel laminated composites: Effects of lamella number and interlamellar spacing

The lamella number and interlamellar spacing are crucial structural parameters in determining mechanical properties of layered nanocomposites, while they are rarely discussed. Herein, we investigate effects of the two parameters on mechanical properties of copper/nickel (Cu/Ni) nano-laminated composites (NLCs) under uniaxial tension using molecular dynamic simulation. The Cu/Ni NLCs with one single Ni laminate exhibit the largest enhancement in Young's modulus (E = 121 GPa) and yield strength (o(z) = 9.8 GPa), attributing to the stronger texture of Ni and interfacial blocking effect on the motion of dislocations. With different Ni layer spacing, the shockley dislocations form a crescent slip plane and enter the Cu matrices along the 45 degrees direction with respect to the Ni laminate. According to the evolution of dislocation length, the flow stress shows a negative relationship with the mean dislocation length. The peak yield strength coincides with the stage of sudden increase of the total dislocation length, indicating decreased mechanical properties with increased dislocation length. These findings provide fundamental relationships between nanoscale laminated structure and macroscopic mechanical properties of Cu/Ni composites, shedding new lights on the rational design of NLCs with enhanced mechanical performances.