High Strength and Radiation Resistant Metal Nanolayered Composite for Next Generation Reactors

Nanolayered composites are known to exhibit ultra high strength and are able to control the strength by controlling the bi-layer spacings. In this study, we developed new material design of metal-graphene nanolayered composite. Graphene is a single-atomic-layer material with excellent mechanical properties, where the strength is reported to be 130 GPa with a modulus of 1TPa, which can enhance the overall strength of the new material. The Cu- and Ni-graphene nanolayered composite have been synthesized by graphene transfer methods with 2 to 5 alternating layers. The strength of the nanolayered composite was revealed by nanopillar compression testing and the results showed ultra-high strengths of 1.5 GPa for copper?raphene with 70-nm repeat layer spacing and 4.0 GPa for nickel?raphene with 100-nm repeat layer spacing. These ultra-high strengths indicate that the single atomic layer graphene effectively blocked dislocation propagation across the metal?raphene interface. Ex-situ and in-situ electron microscopy analyses and molecular dynamics simulations show high intrinsic mechanical strength of graphene provides an effective barrier against dislocation motion despite the fact that it is only a single atomic layer in thickness.