Investigation on deformation behavior of non-crystalline materials via molecular dynamics simulations
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Authors
Zhang, Yanming
Issue Date
2020-12
Type
Electronic thesis
Thesis
Thesis
Language
ENG
Keywords
Materials engineering
Alternative Title
Abstract
This method enables the calculation of viscosity from high to room temperature, where the extracted activation energy of isostructural flow is found to be correlated with Poisson’s ratio, the signature of intrinsic toughness. Next, we designed several toughening strategies for intrinsically brittle glasses such as silica, aluminosilicate, and model metallic glasses. The enhanced toughness for silica and aluminosilicate glasses is achieved by introduced structural and/or chemical heterogeneities via consolidating glassy nanoparticles. We also observed surprising work hardening ability, which is attributed to the stress-facilitated relaxation of plasticity carriers (over-coordinated clusters). In addition, we also designed strong, ductile, and work hardenable composites with exclusively brittle glassy constituents by exploiting stiffness contrast and size effects. Finally, we revealed the tensile plasticity of brittle and ductile glassy nanowires display distinct strain-rate dependency due to the ductile glass possesses more hierarchical fractal potential energy landscape. Our results shed light on how to obtain tough glasses both intrinsically and extrinsically via providing atomic insights.
Description
December 2020
School of Engineering
School of Engineering
Full Citation
Publisher
Rensselaer Polytechnic Institute, Troy, NY