Acta Metallurgica Sinica (English Letters) ›› 2022, Vol. 35 ›› Issue (3): 466-474.DOI: 10.1007/s40195-021-01286-2

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An Ultra-High Strength Over 700 MPa in Al-Mn-Mg-Sc-Zr Alloy Fabricated by Selective Laser Melting

Hao Tang1, Yaoxiang Geng1(), Shunuo Bian1, Junhua Xu1(), Zhijie Zhang1   

  1. 1School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang, 212003, China
  • Received:2021-03-15 Revised:2021-05-31 Accepted:2021-06-02 Online:2021-07-30 Published:2021-07-30
  • Contact: Yaoxiang Geng,Junhua Xu
  • About author:Junhua Xu, jhxu@just.edu.cn
    Yaoxiang Geng, yaoxianggeng@163.com;

Abstract:

Selective laser melting (SLM) provides optimized lightweight structures for aircraft and space applications. However, the strength of the current SLMed aluminum alloys is still lower than that of the traditional high-performance aluminum alloys. This study presents an ultra-high-strength Al-Mn-Mg-Sc-Zr aluminum alloy specifically designed for SLM by increasing the (Mg + Mn) and (Sc + Zr) content simultaneously based on the rapid solidification characteristics of the SLM process. The alloy exhibits good SLM processability with a minimum porosity of 0.23%. After aging at 300 °C, the strength of the alloy was effectively improved, and the anisotropy of mechanical properties was reduced. Additionally, the tensile yield strength and ultimate tensile strength of the alloy reached 621 ± 41 MPa and 712 ± 28 MPa, respectively; these values are superior to those of most SLMed aluminum alloys reported previously. Multiple strengthening mechanisms including solid solution strengthening, precipitation strengthening and grain refinement strengthening contribute to the high strength of the present alloys.

Key words: Selective laser melting, Al-Mn-Mg-Sc-Zr alloy, Aging treatment, Mechanical properties, Strengthening mechanism