Direct synthesis and modification of graphene in Mg melt by converting CO2: A novel route to achieve high strength and stiffness in graphene/Mg composites

Abstract

The processing scale and mechanical properties of graphene (Gr) reinforced metal matrix composites are highly desired for a wide range of critical applications. However, a long-standing problem is that Gr possesses poor dispersibility and weak interfacial strength with the metal matrix. In this work, we offer an in-situ liquid metallurgy strategy for fabricating Mg matrix composites with excellent modulus, strength and plasticity by a chemical reaction between carbon dioxide (CO2) and Mg melt. This processing route enables the in-situ synthesis and modification of Gr in the metal melt simultaneously, which yields an optimal microstructure including uniform dispersion of Gr and strong interfacial bonding between Gr and Mg matrix. This novel approach can be readily adapted to large-scale industrial production of Mg matrix composites and even offers a general design pathway for manufacturing metal matrix composites.