The direct observation of the core region of a propagating fracture crack in glass
CNRS/Saint-Gobain - 39 Quai Lucien Lefranc, 93303 Aubervilliers, France
Accepted: 16 April 1996
We present the first direct observation (at the nanometre scale) of the far end of a crack tip during propagation. This is achieved by use of an Atomic Force Microscope (AFM) in the case of the so-called brittle fracture. Beside the expected elastic deformation of the surface, the data analysis suggests that a plastic behaviour may take place in the vicinity of the flaw, over a distance of about 50 nm. Also, the experimental method presented here permits to accurately follow the motion (velocity and path) of the crack in the sub-critical regime; consequently, this approach is very likely to be of broad interest in the field of fracture.
PACS: 83.50.Tq – Wave propagation, shocks, fracture, and crack healing / 62.20.Mk – Fatigue, brittleness, fracture, and cracks / 61.16.Ch – Scanning probe microscopy: scanning tunneling, atomic force, magnetic, etc
© EDP Sciences, 1996