Ultra-high strength GNP/2024Al composite via thermomechanical treatment

• 5.0 vol.% GNPs/2024Al composites were fabricated by thermomechanical treatment processing technique. • The GNPs/2024Al composites with homogeneous oriented distribution of GNPs were created by multiple drawing after solid solution. • The introducing high-density dislocations in Al grains after six-pass drawing resulted in the enhanced nucleation of precipitates during ageing. • The ultra-high yield strength and ultimate tensile strength of GNPs/2024Al composites reached 482 MPa and 571 MPa, respectively. The 5.0 vol.% GNP/2024Al composites were prepared by accumulated shear deformation combined with heat treatment, i.e. the thermomechanical treatment (TMT). The results showed that homogeneous distributed GNPs that aligned along the plastic deformation direction were obtained by six-pass drawing in the solution heat treatment state. The introducing of high-density dislocations in Al matrix by multiple drawing resulted in enhanced nucleation of precipitates and subsequent uniform growth during ageing. Consequently, ultra-strength GNP/2024Al composites, with yield and ultimate tensile strength 482 and 571 MPa, respectively, were achieved. The high strength was attributed to homogeneous dispersion of undamaged GNPs, fine and dispersed precipitations and work-hardening effect. This work demonstrated that TMT could act as a feasible strategy for preparing high-performance GNP/Al composites.