Faceting of twin interfaces in rolled pure magnesium

ABSTRACT

Recent studies proved that the faceting of twin boundaries is a common feature in hcp materials. It was demonstrated that the asymmetrical facets in the most frequent $\left\{10\overline{1}2\right\}$ and $\left\{10\overline{1}1\right\}$ twin interfaces are the consequence of the twin boundary migration mechanism. We demonstrate that a similar mechanism is also applicable to less common $\left\{11\overline{2}6\right\}$ twins, observed in pure magnesium rolled at room temperature. The migration of $\left\{11\overline{2}6\right\}$ twin boundary is mediated by disconnections, which have Burgers vector $b=0.030\left[11\overline{2}\overline{1}\right]$ and step height equal to four $\left\{11\overline{2}6\right\}$ interplanar distances. The mechanism of asymmetrical facets nucleation is also demonstrated by using atomistic simulations. The simulations are supported by transmission electron microscopy (TEM) of asymmetrical basal-pyramidal interfaces of $\left\{11\overline{2}6\right\}$ twins.

KEYWORDS:

• Magnesium
• twin boundary
• interfaces
• atomistic simulations
• SEM
• TEM

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by the Czech Science Foundation [grant number 18-07140S]. R.V. acknowledges funding from the specific research project Central European Institute of Technology [CEITEC-J-21-7507].