A comparative study of carbon nanotubes and graphene for metal matrix Composites: Insights from simulation and experimentation

Carbon nanotubes (CNTs) and graphene (Gr), as one-dimensional and two-dimensional carbon nanomaterials, respectively, are widely used as reinforcements in metal matrix composites (MMCs). However, their comparative effectiveness in enhancing mechanical properties remains unclear. This study employs molecular dynamics (MD) simulations and experimental tensile testing to evaluate the mechanical behavior of aluminum (Al) matrix composites reinforced with CNTs and Gr (CNT/Al and Gr/Al). MD simulations revealed that Gr/Al composites exhibit superior load transfer efficiency and more uniform stress-strain distribution compared to CNT/Al, attributed to Gr's periodic co-lattice structure at the Al interface. Dislocation analysis showed that Gr/Al forms dislocation tangles, enhancing strength and ductility, while CNT/Al relies on Orowan loops and dislocation cells, leading to strain concentration and reduced performance. Experimentally, Gr/Al composites demonstrated a 36.1 % higher yield strength (196 MPa vs. 144 MPa) and 32 % greater elongation than CNT/Al, consistent with simulation predictions. These findings highlight Gr's superior reinforcement potential, providing critical insights for designing high-performance MMCs for aerospace and automotive applications.