Research progress in preparation technology and mechanical properties of nano-Al2O3 reinforced aluminum matrix composites

As lightweight and high-performance structural materials， nano-Al2O3 reinforced aluminum matrix composites can achieve lightweight energy saving and emission reduction， and have broad application prospects in aerospace， automotive industry， shipbuilding， national defense， and 5G electronic communication. In this paper， high energy ball milling powder metallurgy method， ultrasonic assisted casting method， friction stir method， additive manufacturing method， in-situ reaction method and other nano-Al2O3 reinforced aluminum matrix composite preparation technologies are introduced. The effects of nano-Al2O3 reinforcement， the interface microstructure between the reinforcement and aluminum matrix， the size and content of the reinforcement， the grain size of the aluminum matrix，the dispersion of the reinforcement， and the microstructure design on the mechanical properties of nano-Al2O3 reinforced aluminum matrix composites are analyzed and summarized. The main strengthening mechanisms of nano-Al2O3 reinforced aluminum matrix composites and the coupling forms of each strengthening stress are also summarized. Finally， the future development direction of nano-Al2O3 reinforced aluminum matrix composites in the aspects of large-size preparation technology with high reinforcement volume fraction， heterogeneous configuration optimization， and the integration of high-strength and heat-resistant structure and function are prospected.