Isotropic high-strength aluminum matrix composites reinforced by carbon nanotubes and intra-crystalline nanoparticles

The effective dispersion and distribution control of reinforcements are crucial factors that influence the mechanical properties of metal matrix composites. Here, we propose a strategy to disperse carbon nanotubes in aluminum matrix composites using Ti "nano-grinding balls" as an auxiliary method, achieving the interfacial/ intragranular distribution of nano-reinforcements. Reinforcements with different interfacial/intragranular dimensions can exert different strengthening effects and induce a high density of stacking faults (SFs) by generating high-stress regions within the grains. As a result, the tensile strength and elongation of the as-sintered composite reach -320 MPa and -10%, respectively, while maintaining isotropic properties. This work demonstrates an effective method for creating high-density SFs in high stacking fault energy (SFE) metals through proper reinforcement distribution control.