Mechanism of homogenization temperature and time on Fe-containing phase transition in AA8014 aluminum alloy

• Published in: Materials today communications 2024-12, Vol.41, p.110588, Article 110588
• Main Authors: Huang, Xin, Gao, Chong, Jiang, Xingxu, Li, Liangyu, Gui, Xinghui, Liu, Hui, Yang, Sheng, Zhao, Pizhi, Luo, Hongyun, Ma, Yue
• Format: Article
• Language: English
• Subjects: Aluminum alloy; Fe-containing phase transition; First-principles calculation; Homogenization temperature and time; Thermodynamic and kinetics calculations
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2024.110588

The presence of coarse Fe-containing phases detrimentally affects the fracture toughness of 8xxx aluminum alloys, and their complete dissolution during homogenization is unattainable. Therefore, it is essential to determine the optimal homogenization temperature and time to facilitate particle breakup during hot rolling, necessitating the development of effective homogenization processes. This study systematically examines the effect of homogenization temperature and time on the transition of Fe-containing phases in AA8014 aluminum alloy using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The transition mechanisms of Fe-containing phases during homogenization were elucidated through first-principles calculations, thermodynamics, and kinetics calculations. Under homogenization conditions of 610–650 ℃/12 h and 630 ℃/1–20 h, the Al6(Fe,Mn) phase initially transforms into the α-Al12(Fe,Mn)3Si phase with a “micropore structure” via the reaction. Subsequently, the α-Al12(Fe,Mn)3Si phase transforms into the Al3(Fe,Mn) phase. First-principles calculations confirm the sequential stability enhancement of the Al6(Fe,Mn), α-Al12(Fe,Mn)3Si+6Al, and Al3(Fe,Mn) phases. Homogenization kinetics indicate an optimal homogenization time of 11.5 h at 630 ℃, rationalizing the observed phase transitions and homogenization treatment. This study provides a foundation for the manufacture of 8xxx series aluminum alloys. [Display omitted]