On the dynamics of twinning in magnesium micropillars

Materials & Design

Petr Harcuba¹  Filip Šiška²  Michal Knapek³  Kristián Máthis³  Péter Dusán Ispánovity³  Dávid Ugi⁴  Kwang Seon Shin⁵  István Groma⁵ 

[1] Corresponding author at: Charles University, Faculty of Mathematics and Physics, Department of Physics of Materials, Ke Karlovu 5, 12116 Prague 2, Czech Republic.;Nuclear Physics Institute of the Czech Academy of Sciences, Husinec – Řež 130, 25068 Řež, Czech Republic;Charles University, Faculty of Mathematics and Physics, Department of Physics of Materials, Ke Karlovu 5, 12116 Prague 2, Czech Republic;Institute of Physics of Materials of the Czech Academy of Sciences, CEITEC-IPM, Žižkova 22, 61600 Brno, Czech Republic;Loránd Eötvös University, Department of Materials Physics, Pázmány Péter sétány 1/a., 1117 Budapest, Hungary;

关键词: Magnesium;    Micropillar;    Compression;    Twinning;    Finite element modeling;    Scanning electron microscopy;   

DOI  :  

来源: DOAJ

【 摘 要 】

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 concurrent 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.

【 授权许可】

Unknown