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Title: Deformation mechanisms during nanoindentation of sodium borosilicate glasses of nuclear interest

In this paper we analyze results of Molecular Dynamics simulations of Vickers nanoindentation, performed for sodium borosilicate glasses of interest in the nuclear industry. Three glasses have been studied in their pristine form, as well as a disordered one that is analogous to the real irradiated glass. We focused in the behavior of the glass during the nanoindentation in order to reveal the mechanisms of deformation and how they are affected by microstructural characteristics. Results have shown a strong dependence on the SiO{sub 2} content of the glass, which promotes densification due to the open structure of SiO{sub 4} tetrahedra and also due to the strength of Si-O bonds. Densification for the glasses is primarily expressed by the relative decrease of the Si-O-Si and Si-O-B angles, indicating rotation of the structural units and decrease of free volume. The increase of alkali content on the other hand results to higher plasticity of the matrix and increased shear flow. The most important effect on the deformation mechanism of the disordered glasses is that of the highly depolymerized network that will also induce shear flow and, in combination with the increased free volume, will result in the decreased hardness of these glasses, asmore » has been previously observed.« less
Authors:
;  [1]
  1. CEA Marcoule, DEN/DTCD, Service d’Etude et Comportement des Matériaux de Conditionnement, BP17171 30207 Bagnols-sur-Cèze Cedex (France)
Publication Date:
OSTI Identifier:
22308755
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 1; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; BOROSILICATE GLASS; DEFORMATION; HARDNESS; IRRADIATION; MICROSTRUCTURE; MOLECULAR DYNAMICS METHOD; PLASTICITY; ROTATION; SILICA; SILICATES; SILICON OXIDES; SIMULATION; SODIUM