Surface damage resistance of gel-derived oxycarbide glasses: Hardness, toughness, and scratchability - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of the American Ceramic Society Année : 2001

Surface damage resistance of gel-derived oxycarbide glasses: Hardness, toughness, and scratchability

Résumé

Gel-derived oxycarbide glasses have atomic network structures similar to that of vitreous silica glass but with carbon-rich regions consisting of CSi4 tetrahedra and C-Si-O bonds finely dispersed in the glass. Therefore, oxycarbide glasses exhibit the so-called "anomalous" hardness behavior, similar to silica-rich glasses, with a substantial densification-strain component beneath the indenter. However, the role of carbon is twofold: on the one hand, the covalently bonded carbon atoms slightly affect the behavior, similar to the way network modifiers affect the behavior of silicate glasses, and favor a "normal" indentation behavior; and on the other hand, the free carbon, forming turbostratic graphite domains, provides easy crack initiation sites and low-energy fracture paths. Almost concentric shear steps and microcracks, which follow the turbostratic graphite domains, are observed after indentation. The ultimate coalescence of the microcracks produces Hertzian-tv pe cone cracks.
Fichier non déposé

Dates et versions

hal-01148248 , version 1 (04-05-2015)

Identifiants

  • HAL Id : hal-01148248 , version 1

Citer

Tanguy Rouxel, Jean-Christophe Sangleboeuf, Jean-Pierre Guin, V. Keryvin, G. D. Soraru. Surface damage resistance of gel-derived oxycarbide glasses: Hardness, toughness, and scratchability. Journal of the American Ceramic Society, 2001, 84 (10), pp.2220--2224. ⟨hal-01148248⟩
72 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More