Improving the high-temperature ductility of Al composites by tailoring the nanoparticle network

Al-matrix composites with networked ceramic nanoparticles have been reported to possess high thermal stability, but their low ductility at high temperatures limits their wide applications. In this study, rotary swaging (RS) was used to modify the network of AlN_p nanoparticles for optimizing the high temperature tensile properties of Al matrix composites. The RS treatment was found to disperse the network structure of AlN_p particles to some extent and to refine the grains of Al matrix, which resulted in high strain hardening and strain rate sensitivity. This not only improved the thermal stability but also increased the uniform elongation from 0.99% to 2.1% at 350 °C. This work provides a new pathway for tailoring the nanoparticle architecture to obtain a desirable strength-ductility synergy for metal matrix composites.