Achieving high strength and modulus in graphene reinforced Mg matrix composites via an in-situ process

Magnesium matrix composites reinforced with graphene have attracted great attention because of their fascinating properties. However, it is still challenging to realize the effective addition and dispersion of graphene in the Mg matrix. In this work, a novel in-situ liquid metallurgical process that converts CO2 to graphene is developed to fabricate Mg matrix composites. Firstly, graphene coated with MgO nanoparticles could be produced during the in-situ process, promoting the uniform dispersion of graphene and strong interfacial bonding simultaneously. Furthermore, the fine grain size and dynamic precipitates were formed in the as-extruded composites. Finally, the in-situ formed graphene in the composites shows much higher strengthening efficiency than reinforcements prepared by conventional methods reported so far. This preparation strategy is both efficient and environmentally friendly, and it is suitable for expanding the industrial production of Mg matrix composites. •A novel liquid metallurgical process via in-situ CO2/Mg reaction to produce the graphene reinforced Mg matrix composites.•The composites realize the uniform dispersion of graphene because of MgO nanoparticles coated graphene structure.•The fine grain size and dynamic precipitates were formed in the as-extruded composites.•Composite exhibited excellent room temperature and high temperature strength compared with the Mg alloy.