Nano-tribological behavior of graphene nanoplatelet-reinforced magnesium matrix nanocomposites

The corrosion resistance and wear resistance of metallic biomaterials are critically important for orthopedic hard-tissue replacement applications because the lack of such properties not only adversely affects their mechanical integrity but also allows the release of wear debris into the human body. In this study, the potential of zirconium (Zr) as an alloying element and graphene nanoplatelets (GNPs) as a nano-reinforcement material were investigated in relation to improving the tribological performance of pure magnesium (Mg). The GNPs-reinforced Mg matrix nanocomposites (MNCs) were fabricated using powder metallurgy. Results indicate that additions of 0.5 wt.% Zr and 0.1 wt.% GNPs to Mg matrices significantly improved the wear resistance by 89% and 92% at 200 mu N load, 60% and 80% at 100 mu N load, and 94% and 93% at 50 mu N load, respectively, as compared to the wear resistance of pure Mg. The wear depth and coefficient of friction of the MNC containing 0.5 wt.% Zr and 0.1 wt.% GNPs (Mg0.5Zr0.1GNPs MNC) were considerably reduced as compared to pure Mg and Mg0.5Zr. Our results demonstrate that the Mg0.5Zr0.1GNPs MNC is promising for orthopedic applications in relation to its excellent tribological performance. (C) 2020 Chongqing University. Publishing services provided by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.