A Review on Age Hardening Behavior and Micro-Mechanisms in Aluminum Alloys

Aluminums alloys, as core structural materials in aerospace, automotive manufacturing, and other fields, have their age hardening technology realizing the synergistic optimization of strength and comprehensive properties by regulating the evolution of microstructures, which has long been a research hotspot in the field of materials science. Solution treatment and aging are the core heat treatment methods for aluminum alloys to achieve high strength. There essence lies in controlling the precipitation process of second-phase particles in the aluminum alloy matrix to form nano-scale dispersed precipitates, thereby hindering dislocation movement and significantly improving the strength and hardness of the alloy. This paper systematically reviews the basic principles of age hardening of aluminums alloys, the aging behavior characteristics of typical alloy systems, the multi-scale research progress of micro-mechanisms, as well as the latest achievements in process optimization and performance regulation. It focuses on analyzing the precipitation sequence of different alloy systems，the regulatory effect of micro-alloying elements, and the correlation mechanism between multi-scale microstructures and macro properties. Finally, the future development trends of this field in atomic-scale precise design and intelligent process regulation are prospected, providing theoretical references for the research and development as well as engineering application of high-strength and high-toughness aluminum alloy.