ESPCI web site
Matteo Ciccotti du Laboratoire Sciences et Ingénierie de la Matière Molle
Résumé :
Water molecules play a fundamental role in the physics of slow crack propagation in glasses. In the stress-corrosion theory water molecules that move in the crack cavity act to reduce the bond strength at the strained crack tip and thus enhance crack propagation by thermal activation (Charles and Hillig, 1962). In most cases, the phenomenological equations determined by Wiederhorn (1967) can explain the dependence of crack velocity on stress and environmental parameters, along with the presence of a transport-limited region in the KI-v curve. Yet the fundamental rupture mechanisms acting at the tip are still debated and the influence of glass chemical composition on the fracture properties is still lacking a comprehensive explanation. The recent development of advanced equipments to study in-situ crack growth by AFM in controlled atmosphere have furnished exciting new insights into the nature of stress-corrosion mechanisms at nanoscale, concerning water enhanced nanoductility, stress induced ion migration and corrosive wetting in the crack cavity. However, it was only through a complete multiscale mechanical analysis, combining AFM studies, optical profilometry and finite element simulations, that a coherent quantitative scenario has been made possible providing several answers to active debates.
Rendez-vous lundi, 29 novembre 2010 à 11h10
ESPCI ParisTech, Salle de réunion, Bâtiment F, Pièce F3.04
Contact : mathilde.reyssat[at]espci.fr