J. Mater. Sci. Technol. ›› 2021, Vol. 60 ›› Issue (0): 222-229.DOI: 10.1016/j.jmst.2020.05.026

• Research Article • Previous Articles    

Diffusion growth of ϕ ternary intermetallic compound in the Mg-Al-Zn alloy system: In-situ observation and modeling

Kaiming Chenga,*(), Jiaxing Suna, Huixia Xub, Jin Wanga, Chengwei Zhana, Reza Ghomashchia,c, Jixue Zhoua,*(), Shouqiu Tanga, Lijun Zhangd, Yong Dua,d   

  1. a Shandong Provincial Key Laboratory of High Strength Lightweight Metallic Materials, Advanced Materials Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China
    b Engineering Research Center of Failure Analysis and Safety Assessment, Shandong Analysis and Test Center, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China
    c School of Mechanical Engineering, The University of Adelaide, Adelaide SA 5005, Australia
    d State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
  • Received:2019-12-31 Revised:2019-12-31 Accepted:2019-12-31 Online:2021-01-10 Published:2021-01-22
  • Contact: Kaiming Cheng,Jixue Zhou

Abstract:

Study on the diffusion growth of ternary intermetallic compounds in Mg-Al-Zn based light-weight alloys is important due to its close interrelation with alloy property. However, there is a very lack of existing data due to difficulties in both experimental and computational aspects. The current work aims at presenting the experimental observation on the diffusion growth behavior of ? phase at 360 °C as well as calculating its composition-dependent interdiffusion coefficients. We designed and successfully fabricated four Mg-τ ternary diffusion couples annealed at 360 °C for different times, where the diffusion path goes across the ? phase region and the diffusion growth of ternary intermetallic compound can be solely detected. In-situ observation of the time-dependent growth of ? phase was performed to accurately determine the parabolic growth constant. The experimental data were then subjected to a numerical inverse method to generate a set of self-consistent interdiffusivities of the ternary intermetallic compounds, which can reproduce the presently observed diffusion growth behavior of ? ternary intermetallic compound in Mg-τ diffusion couples.

Key words: Diffusion, Intermetallic compounds, Interface migration, Numerical inverse methods, High-temperature laser-scanning confocal microscopy (HTLSCM)