High content reduced graphene oxide reinforced copper with a bioinspired nano-laminated structure and large recoverable deformation ability.

Ding-Bang Xiong,Mu Cao,Zhiqiang Li,Di Zhang,Zhanqiu Tan,Qiang Guo,Genlian Fan

doi:10.1038/srep33801

Abstract

By using CuO/graphene-oxide/CuO sandwich-like nanosheets as the building blocks, bulk nacre-inspired copper matrix nano-laminated composite reinforced by molecular-level dispersed and ordered reduced graphene oxide (rGO) with content as high as ∼45 vol% was fabricated via a combined process of assembly, reduction and consolidation. Thanks to nanoconfinement effect, reinforcing effect, as well as architecture effect, the nanocomposite shows increased specific strength and at least one order of magnitude greater recoverable deformation ability as compared with monolithic Cu matrix.

Highlights

Both theoretical[39] and experimental[27,40] results have proven the high reinforcing efficiency of graphene in metal matrix
In spite of great successes demonstrated by the metal matrix composites with graphene at low contents, composites with highly concentrated and ordered graphene are desired because: 1) biological materials is clearly inspiring for their ability to achieve novel properties by constructing such architecture with high content and ordered nanofiller; 2) ordering graphene implies higher reinforcing efficiency43; 3) high content graphene implies high density of interfaces for blocking dislocation motion being the dominant deformation mode in metals; 4) nanoconfinement effect benefited from high interface density makes it possible to transfer extraordinary properties of constituents at nanoscale to macroscale
Due to its large surface area and high surface energy that lead to agglomerations and restacking, as well as notable density difference between graphene and metals, it is extremely difficult to disperse graphene into metals homogeneously

Summary

Introduction

Both theoretical[39] and experimental[27,40] results have proven the high reinforcing efficiency of graphene in metal matrix. Simultaneous improvements on strength and toughness were achieved in our rGO/Cu41 and rGO/Al42 artificial nacres, in which the reinforcing efficiency of rGO was remarkably higher than that in the composites containing randomly dispersed rGO. We present a strategy for fabricating bulk rGO-Cu nano-laminated composite with high rGO content (∼45 vol%) by bottom-up assembly and reduction of CuO/GO/CuO sandwich-like nanosheets. This process technique realized simultaneous uniform dispersion and ordering of high content graphene in metal matrix. Its microstructure and mechanical properties were characterized and discussed, and the as-obtained bulk nano-laminated composite exhibited recoverable deformation strain at least one order of magnitude greater than that of pure copper as well as increased specific strength because of high content graphene

Methods

Results

Conclusion