Superb mechanical properties of a novel high-Zn Al alloy processed via two-step thermomechanical treatments

• Published in: Materials letters 2024-08, Vol.369, p.136747, Article 136747
• Main Authors: Wang, Feng, Zhang, Xiaoqiang, He, Junyang, Huang, Dongnan, Rahimov, Rustam V., Mansurov, Yulbarskhon N., Wang, Zhangwei, Song, Min
• Format: Article
• Language: English
• Subjects: Al alloys; Cast; Mechanical properties; Microstructure; Precipitation strengthening; Thermo-mechanical treatments
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2024.136747

[Display omitted] •A novel high Zn Al alloy is processed via two-step thermo-mechanical treatments.•A dense distribution of η’ precipitates is achieved due to the unique processing.•A superhigh ultimate tensile strength up to 789 MPa is attained. Precipitation strengthening is crucial for the high strength of Al-Zn-Mg-Cu (7xxx) alloys. In this study, we synthesized a novel high-Zn 7xxx Al alloy through a comprehensive two-step thermo-mechanical treatment that includes hot extrusion and hot rolling. This approach effectively mitigates casting defects caused by high Zn content and preserves a significant number of dislocations and low-angle grain boundaries. These deformation substructures, coupled with high Zn concentrations, promote the dense formation of η’ nanoprecipitates. As a result, this alloy exhibits an exceptional combination of mechanical properties, with an ultimate tensile strength (UTS) of 789 MPa and a tensile elongation of 9.2 %. Our findings offer innovative insights into the design of ultra-strong and ductile Al alloys for advanced engineering applications.