Governing high-content nanoparticles distribution for architecting high-performance bamboo-structured 2024Al matrix composites

Fabricating high-content nanoparticle-reinforced aluminum matrix composites with balanced modulus–strength–ductility has been a long-standing challenge. Inspired by natural biostructures, an inversed bamboo configuration combined with high-content nano-dispersoids was proposed, featuring fiber-like soft bands embedded into hard matrix and exhibiting 94.88 GPa in Young’s modulus, 709 MPa in yield strength and 7.21% in elongation. The sustained strain hardening behavior led to an improved uniform elongation even at such high stress levels. The underlying mechanisms for superior mechanical properties include biostructural hetero-deformation induced (HDI) strengthening/hardening, intragranular nano-dispersoids enhanced dislocation storage of ultrafine grains and SiC/Al interfaces induced stacking faults. A novel bamboo-inspired structure was designed for the first time to achieve an excellent strength-modulus-ductility combination in high-content SiCnps/Al-Cu-Mg composites. • High-content nanoparticle-reinforced aluminum matrix composite (AMC) with a high-performance by architecting an inverse bamboo structure has been reported for the first time. • A sustained strain hardening behavior of high-content nanoparticle-reinforced AMC was observed, resulting in an enhanced uniform elongation with such high yield levels. • The introduction of high-content nanoparticles facilitates the dislocation storage of ultrafine grains and the generation of stacking faults, leading to a high strain hardening rate.