Microstructural Control, Property Trade-Offs and Emerging Design Strategies in Conventional Aluminum Alloys.

Traditional aluminum alloys have a mature industrial system, but their properties are still constrained by factors such as precipitation behavior, the grain boundary state, solidification defects, and residual impurities. This paper systematically reviews the microstructure formation, strengthening mechanisms, and performance regulation laws for major wrought and casting aluminum alloys. It also compares the characteristics of different alloy systems in terms of strength, ductility, corrosion resistance, fatigue performance, and manufacturing stability. The analysis shows that the development focus for traditional aluminum alloys has shifted from single performance improvement to multi-performance balance and precise control of the microstructure. With the increase in the proportion of recycled raw materials, the importance of impurity tolerance and the controllable transformation of second phases has further increased. At the same time, CALPHAD, physical models, and data-driven methods provide new means for alloy composition and process optimization, but their effectiveness still needs to be verified in actual components and engineering conditions. This paper can provide a reference for microstructure design, material selection, and performance optimization for the circular manufacturing of traditional aluminum alloys.