中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 35 No. 11 November 2025 |
（1. College of Materials Science and Engineering, Guilin University of Technology, Guilin 541004, China;
2. Key Laboratory of New Processing Technology for Nonferrous Metal & Materials, Ministry of Education, Guilin University of Technology, Guilin 541004, China;
3. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
4. Engineering Research Center of Advanced Aluminum Matrix Materials of Guangxi, Baise University, Baise 533000, China）
Abstract:The microstructure evolution and strengthening ability of natural aging (NA), delayed aging (DA), and DA after pre-aging (PDA) of Al-Mg-Si alloy were studied. Results show that small and unstable atomic clusters are generated during NA, leading to the formation of low-density coarse β？ and β′ phases, thus reducing the strength of DA alloy. However, atomic clusters and GP zones with larger sizes and high Mg/Si molar ratio form during pre-aging treatment. They prevent the generation of clusters during NA and can serve as effective nucleation sites in subsequent artificial aging, which elevates the number density of fine β？ precipitates and improves the alloy strength. After pre-aging at 175 °C, the strengthening capacity of PDA alloy is restored, with hardness and yield strength reaching 95.1% and 101.9% of peak-aged alloy.
Key words: pre-aging; delayed aging; precipitate; microstructure evolution; strengthening ability; Al-Mg-Si alloy
