Interface design of graphene/copper composites by matrix alloying with titanium

The attainment of intimate and strong interface is critical for promoting the load transfer ability and strength of graphene/metal composites. Herein, we reported an interface design strategy by matrix-alloying with Ti for in-situ interfacial carbide formation in reduced graphene oxide (RGO)/CuTi composites. It was demonstrated that both Ti8C5 nanolayers and Ti8C5 nanoparticles were in-situ formed at the local interface of RGO/CuTi composite, which played a rivet role in enhancing the interfacial bonding between the RGO and CuTi matrix. At 1.5 vol% RGO loading, compared to RGO/Cu composite without alloying, the RGO/CuTi composite exhibited a higher enhancement in tensile strength (57.7% vs. 37.5%) and a lower reduction in coefficient of thermal expansion (-10.9% vs. -3.9%). The formed interfacial Ti8C5 nanolayers and Ti8C5 nanoparticles were proposed to originate from the amorphous carbon nanolayers and amorphous carbon nanoparticles on the surface of RGO, respectively. This study provides new insights into the interface design and carbide formation mechanism of advanced graphene/Cu composites with enhanced mechanical/thermal properties. (C) 2018 Elsevier Ltd. All rights reserved.