2016-Sustainable Industrial Processing Summit
SIPS 2016 Volume 7: Yang Intl. Symp. / Multiscale Material Mechanics
| Editors: | Kongoli F, Aifantis E, Wang H, Zhu T |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2016 |
| Pages: | 190 pages |
| ISBN: | 978-1-987820-48-5 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Co-deformation mechanisms in crystalline-amorphous nanolaminates
Xiaoyan Li1;1, Beijing, China;
Type of Paper: Regular
Id Paper: 444
Topic: 1
Abstract:
The crystalline-amorphous nanolaminates have been fabricated by incorporating the metallic glasses with the polycrystalline metals. Such kind of nanocomposite exhibits high strength and good ductility. However, the underlying deformation mechanisms in these nanocomposites are not well understood. Here we performed a series of large-scale molecular dynamic simulations to investigate the compressive deformation of crystalline-amorphous nanopillars consisting of alternating nanocrystalline Cu and amorphous Cu50Zr50 layers with the identical thickness. The simulation results show that the strength of material exhibits a maximum at the thickness of 3-5 nm. The atomistic simulations also reveal that as the layer thickness decreases, there exists a deformation mechanism transition from the local shear banding in individual amorphous layers to the co-deformation in both crystalline and amorphous layers. In the co-deformation regime, dislocation and shear transformation zone (STZ) are activated simultaneously in the crystalline and amorphous layers, respectively. There exists a complex interaction between dislocation and STZ through the crystalline-amorphous interface, to ensure plastic strain compatibility on the interface. A theoretical model involving dislocation slip and shear banding was proposed to explain the dependence of strength on the layer thickness.