Effect of CNT embedding angle on tensile behavior and dislocation mechanisms in magnesium matrix composites: a molecular dynamics study

• A strategy to predict the mechanical properties and deformation mechanisms of CNT-reinforced magnesium matrix composites from an atomic perspective was proposed. • Influence mechanism of CNT embedded angle on the deformation mechanism and dislocation evolution of metal matrix composites was systematically discussed. • CNT/Mg composite was constructed to identify the role of reinforcement on the strengthening mechanisms of the composite. This study explores the influence of CNT embedding angles on the tensile behavior and dislocation evolution of CNT/Mg composites using molecular dynamics simulations. The results reveal that CNTs aligned parallel to the tensile loading direction significantly enhance the composite’s tensile strength and stiffness, with the maximum tensile strength of 6.07 GPa and a Young’s modulus of 90.01 GPa at 0° embedding. As the embedding angle increases, the tensile strength decreases, while the Young’s modulus exhibits non-monotonic variations. At low angles, CNTs enable efficient load transfer, thereby reinforcing the matrix, while at larger angles, their load transfer efficiency diminishes, leads to stress localization and potential interface debonding. The dislocation evolution analysis shows that CNTs serve as dislocation traction at small angles, but at higher angles, they act as dislocation obstacles, leading to dislocation entanglement and local damage. These findings highlight the complex interplay between load transfer efficiency and dislocation mechanisms, offering insights for optimizing CNT orientation in composites to enhance mechanical performance. Future studies should focus on improving interface adhesion and tailoring CNT distributions for maximum strengthening effects