On the dynamics of twinning in magnesium micropillars

0542590 - ÚJF 2022 RIV GB eng J - Journal Article
Máthis, K. - Knapek, Michal - Šiška, Filip - Harcuba, P. - Ugi, D. - Ispanovity, P. D. - Groma, I. - Shin, K. S.
On the dynamics of twinning in magnesium micropillars.
Materials and Design. Roč. 203, MAY (2021), č. článku 109563. ISSN 0264-1275. E-ISSN 1873-4197
R&D Projects: GA ČR(CZ) GA18-07140S; GA MŠMT EF16_013/0001794
Institutional support: RVO:68081723 ; RVO:61389005
Keywords : magnesium * compression * twinning * finite element modeling * scanning electron microscopy
OECD category: Materials engineering; Materials engineering (UFM-A)
Impact factor: 9.417, year: 2021
Method of publishing: Open access
https://doi.org/10.1016/j.matdes.2021.109563

Micro-deformation testing has recently gained far-reaching scientific importance as it provides intrinsic information on the dynamics of plastic deformation which is concealed when bulk materials are tested. In this work, single-crystal Mg micropillars favorably oriented for mechanical twinning were tested in compression with con-current scanning electron microscopy imaging. The experimental data were complemented by the finite element modeling in order to reveal the underlying physical background of the observed twinning dynamics. It was shown that the thickness of a twin should reach a critical value before triggering the nucleation of another twin to accommodate further strain. Nucleation and growth are repeated until the twins form throughout the whole micropillar, from top to bottom. Afterwards, the thickening and coalescence of all these twins take place until the entire micropillar volume is twinned. In addition, a line-by-line analysis of the scanning electron microscopy images was employed to reveal the twin lateral growth rates, which were shown to be on the order of 10(-5)-10(-4) m/s.
Permanent Link: http://hdl.handle.net/11104/0319975