Achieving high strength-ductility synergy through high-density coherent precipitation in twin-roll cast Al–Zn–Mg–Cu strips

Yuan Ting Mo, Cheng Wang, Shao You Zhang, Xu Liu, Min Zha, Jun Hua Luan, Zeng Bao Jiao, Hui Yuan Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

Achieving dense coherent precipitates in 7xxx aluminum alloys during artificial aging to attain high strength-ductility synergy remains a challenging task as they are unstable and tend to dissolve or transform to the semi-coherent phase. Here, we successfully obtained high-density (1.32 × 1024 m−3) and fine-sized (∼4.1 nm) coherent precipitates in the twin-roll cast Al-6.3Zn-3.3Mg-1.8Cu (wt.%) alloys through pre-strain and subsequent artificial aging, i.e. strain aging. Therefore, the peak-aged sample exhibited a satisfactory tensile strength of ∼600 MPa and extraordinary fracture elongation of ∼15%. The inconspicuous interface between coherent precipitates and the Al matrix reduces the tendency of interfacial stress concentration, which ensures high room temperature ductility. The strengthening mechanism was calculated by the dislocation shearing model, indicating that coherent precipitates contribute ∼80% of the total yield strength. This work could provide a short-process and low-budget method for preparing high-performance 7xxx series alloy strips.

Original languageEnglish
Article number143592
JournalMaterials Science and Engineering A
Volume850
DOIs
Publication statusPublished - 11 Aug 2022

Keywords

  • Al-Zn-Mg-Cu alloy
  • Coherent precipitates
  • Mechanical properties
  • Twin-roll casting

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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