The synergistic impact of graphene and copper on microstructure, corrosion behaviors and biocompatibility of a magnesium metal matrix composite in Hank's solution

Background: This research aimed to explore the combined effects of graphene (Gr) and copper (Cu) in a magnesium metal composite (MMC) on its microstructure, biocompatibility, electrochemical, and immersion corrosion behaviors. Methods: The MMCs were prepared using the mechanical stir-casting method. Alloys with a preset weight percentage of Gr (0.15 wt.%) and various weight percentages of Cu (0.5 and 1 wt.%) were produced with pure Mg as the matrix. Significant findings: This study demonstrates that Gr and Cu enhance crystallinity and increase grain size in composite materials. The introduction of Gr into the magnesium matrix alone elevates the corrosion rate. However, there was a further addition of 0.5 wt.% Cu (0.5Cu) showed a slight reduction in grain size growth and corrosion rate. The addition of more copper (1 wt.% Cu (1Cu)) increases both grain size and the corrosion rate again. Cytotoxicity test results indicate that Gr and Cu enhance the cell viability of 3T3 fibroblasts in vitro. These findings shed light on the intricate interplay between Gr and Cu in the microstructure and corrosion resistance of Mg-based composites and inspire confidence in developing magnesium metal composites for clinical applications.