Interactions between long-period stacking ordered phase and β′ precipitate in Mg–Gd–Y–Zn–Zr alloy: Atomic-scale insights from HAADF-STEM

• The general morphology of this alloy is 3-D network composed of β′β′ and LPSO.
• Three types of interactions between β′β′ and LPSO are fully revealed.
• The LPSO that interfaces with α-Mg matrix may have unique characteristics.

This paper reports on an atomic-scale investigation into the interactions between β′β′ precipitates and long-period stacking ordered phase (LPSO) in Mg–10Gd–5Y–2Zn–0.5Zr (wt%) alloy, using Cs-corrected high angle annular dark field-scanning transmission electron microscopy (HAADF-STEM). The general morphology within the alloy is LPSO phase intercalated with β′β′ precipitates and the two structures interconnect into a 3-D network. The β′β′/LPSO interactions are fully characterized and categorized into three types: RE-absent gaps parallel to (112¯0)Mg, redistributions of heavy atoms within LPSO structures and interceptions of β′β′ precipitates by LPSO structures from [101¯0]Mg direction.

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