Crack-Tip Shielding by Swelling in Silica Proved from Measurement of Crack-Terminating Angles in DCDC-Tests

Cracks terminating at free surfaces are affected by local stresses in the surface region. Under residual compression, the crack front must retard, whereas residual tensile stresses lead to an advance, both compared with the crack contour in the absence of stresses. This effect can be used for an est...

Full description

Saved in:
Bibliographic Details
Published inGlass physics and chemistry Vol. 48; no. 1; pp. 30 - 34
Main Authors Hettich, P., Schell, K. G., Bucharsky, E. C., Rizzi, G., Wagner, S., Fett, T.
Format Journal Article
LanguageEnglish
Published Moscow Pleiades Publishing 01.02.2022
Springer Nature B.V
Subjects
Ceramics
Characterization and Evaluation of Materials
Chemistry and Materials Science
Composites
Compressive properties
Crack tips
Free surfaces
Glass
Heat treatment
Materials Science
Natural Materials
Physical Chemistry
Silicon dioxide
Stress intensity factors
Swelling
Water
Water vapor
residual surface stresses
shielding stress intensity
crack-terminating angles
Online AccessGet full text

Cover

More Information
Summary:Cracks terminating at free surfaces are affected by local stresses in the surface region. Under residual compression, the crack front must retard, whereas residual tensile stresses lead to an advance, both compared with the crack contour in the absence of stresses. This effect can be used for an estimation of residual surface stresses in silica generated during the silica/water reaction and caused by volume swelling. A strong shielding stress intensity factor of about –2.5 MPa√m was found for Double Cleavage Drilled Compression specimens heat-treated for 192 h at 250°C in water vapour under saturation pressure and in liquid water. This result is a clear indication for compressive stresses developing in the water diffusion zone at the surface.
ISSN:1087-6596
1608-313X
DOI:10.1134/S1087659622010060