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Strengthening effect of single-atomic-layer graphene in metal–graphene nanolayered composites

2013; Nature Portfolio; Volume: 4; Issue: 1 Linguagem: Inglês

10.1038/ncomms3114

2041-1723

Youbin Kim, Jinsup Lee, Min Sun Yeom, Jae Won Shin, Hyungjun Kim, Yi Cui, Jeffrey W. Kysar, James Hone, Yousung Jung, Seokwoo Jeon, Seung Min Han,

Microstructure and mechanical properties

Graphene is a single-atomic-layer material with excellent mechanical properties and has the potential to enhance the strength of composites. Its two-dimensional geometry, high intrinsic strength and modulus can effectively constrain dislocation motion, resulting in the significant strengthening of metals. Here we demonstrate a new material design in the form of a nanolayered composite consisting of alternating layers of metal (copper or nickel) and monolayer graphene that has ultra-high strengths of 1.5 and 4.0 GPa for copper–graphene with 70-nm repeat layer spacing and nickel–graphene with 100-nm repeat layer spacing, respectively. The ultra-high strengths of these metal–graphene nanolayered structures indicate the effectiveness of graphene in blocking dislocation propagation across the metal–graphene interface. Ex situ and in situ transmission electron microscopy compression tests and molecular dynamics simulations confirm a build-up of dislocations at the graphene interface. Suppressing the movement of dislocations is critical in enhancing the strength of crystalline metals. Kim et al. demonstrate in Cu– and Ni–graphene nanolayered systems that single-layer graphene is effective in suppressing dislocation movement, resulting in a maximum strength of 4.0 GPa.