Synergistic enhancement of modulus and ductility in Mg matrix composites: A new strategy for GNPs&MgOnp and SiCp hybrid reinforcement

Abstract

SiC particles (SiCp) reinforced magnesium matrix composites (MMCs) exhibit elevated specific stiffness. However, the non-uniform distribution of SiCp and the interfacial cracking between the SiCp and Mg matrix compromise the ductility. This paper presents a novel approach to enhance the modulus and ductility of the MMCs by utilizing in-situ synthesized graphene nanoplatelets (GNPs) and MgO nanoparticles (MgO_np). The in-situ reaction of GNPs and MgOnp (GNPs&MgO_np) conducted at a high temperature (720 °C) demonstrates an improvement in the local agglomeration of SiCp compared to the conventional semi-solid temperature (590 °C). Moreover, the GNPs&MgO_np optimized interfacial structure and transferred the load during plastic deformation, inhibiting stress concentration and crack propagation at the interface of SiCp. The ductility and modulus are enhanced by approximately 70 % and 10 % compared to SiCp/Mg-6Zn composites, demonstrating the effectiveness of the strategy employing micro-nano hybrid reinforcement and synergistic enhancement of ductility and modulus.