Unravelling the local ring-like atomic pattern of twin boundary in an Mg-Zn-Y alloy

ABSTRACT

Understanding the interactions between deformation twins and plate-like phases in magnesium alloys is one of the key issues to tailor the microstructure of magnesium alloys for better mechanical properties. The {10$\overline{1}$2} twin boundary with the local ring-like atomic pattern in magnesium alloy, accompanied by the interaction between deformation twin and solute atoms, has been investigated using aberration-corrected scanning transmission electron microscopy. We found that these boundaries featured local overlapping morphology near the intersection between deformation twins and stacking faults (SFs) enriched with solute atoms. The overlapping morphology is proposed to be induced by the asynchronous shuffling of the SFs and matrix during the twinning. The local ring-like atomic patterns shown here imply that the shearable specific SFs in magnesium alloys will increase twinning energy and resultantly hinder twinning propagation.

KEYWORDS:

• Magnesium alloy
• deformation twin
• long period stacking ordered (LPSO) phase
• stacking fault
• HAADF-STEM

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 51871222], [grant number 51301177], the Fund of SYNL [grant number 2017FP16], JSPS Postdoctoral Fellowship for Overseas Researchers [grant number P17732], and is partially supported by JSPS KAKENHI [grant number JP16K06775].