J. Mater. Sci. Technol. ›› 2018, Vol. 34 ›› Issue (12): 2235-2239.DOI: 10.1016/j.jmst.2018.06.015

• Orginal Article • Previous Articles     Next Articles

A 12R long-period stacking-ordered structure in a Mg-Ni-Y alloy

Cheng Liua, Yuman Zhub1, Qun Luoa, Bin Liua, Qinfen Guc, Qian Lia*()   

  1. a State Key Laboratory of Advanced Special Steels, Shanghai Key Laboratory of Advanced Ferrometallurgy, School of Materials Science and Engineering, Shanghai Institute of Materials Genome, Materials Genome Institute, Shanghai University, Shanghai 200444, China
    b Department of Materials Science and Engineering, Monash University, Victoria 3800, Australia
    c Australian Synchrotron, Clayton 3168, Australia
  • Received:2018-06-12 Revised:2018-06-15 Accepted:2018-06-17 Online:2018-12-20 Published:2018-11-15
  • Contact: Li Qian


A hitherto unreported long-period stacking-ordered (LPSO) phase, designated 12R, was observed in a Mg80Ni5Y15 (at.%) alloy. Microstructure was investigated by electron diffraction and high-angle annular dark-field scanning transmission electron microscopy. Results show that the 12R has a trigonal lattice (a = b = 1.112 nm, c = 3.126 nm, α = β = 90°, and γ = 120°). Unit cell of the 12R is consisted of three ABCA-type building blocks and each building block contains dominant Ni6Y8-type building clusters. A sound structural model is proposed based on relative positions of Ni6Y8 clusters in neighboring building blocks.

Key words: Mg alloys, LPSO, HAADF-STEM, Crystal structure