Insight into ultra-refined grains of aluminum matrix composites via deformation-driven metallurgy

Ultra-refined grains were obtained in few-layer graphene nanoplatelets reinforced aluminum matrix composites via deformation-driven metallurgy under coupled thermo-mechanical effect. Fragmentation, thinning and re-dispersion of the reinforcements accelerated the nucleation of recrystallized grains and inhibited the migration of grain boundaries. The synergy grain refinement mechanism led to a greatly refined microstructure with an average grain size of 267.0 nm, which was much smaller than the grain size of conventional aluminum matrix composites to realize high strengthening-toughening efficiency. This novel preparation route showed the capacity of developing ultra-fine aluminum matrix composites with the exceptional grain refinement towards ultra-lightweight design.