Abstract
In this study, an Al-5.5Zn-2.2Mg-1.2Cu-0.12Zr (wt%) alloy with a high dislocation density was successfully fabricated by twin-roll casting (TRC). The effects of two-stage homogenization processes on the precipitation behavior of the L12-structured Al3Zr phase and recrystallization in this Al-Zn-Mg-Cu-Zr alloy were investigated. Furthermore, the influences of the Al3Zr and recrystallization levels on the mechanical properties and intergranular corrosion (IGC) resistance were evaluated. Based on the obtained results, compared to conventional single-stage homogenization, the two-stage homogenization significantly enhanced the precipitation of Al3Zr due to the higher driving force and greater number of heterogeneous nucleation sites provided for the precipitation in the first stage. Therefore, the number density and volume fraction of Al3Zr increased significantly. Additionally, the holding times at the different stages affected the precipitation of Al3Zr. As the first-stage time increased, the number density and volume fraction of Al3Zr increased and then decreased, which was caused by the evolution of heterogeneous nucleation sites (T phase). As the second-stage time increased, the nucleation, growth, and Ostwald ripening of Al3Zr occurred. Variations of the fv/r ratio of the Al3Zr phase led to different recrystallization resistances during the solution treatment. Therefore, partially recrystallized microstructures were achieved in the two-stage homogenized alloys after the T6 treatments. These microstructures and the corresponding distributions of Al3Zr slightly affected the mechanical properties, while they significantly improved the IGC resistance.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
