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Kinetics of Crack Tip Blunting of Glasses
Author(s) -
HIRAO KAZUYUKI,
TOMOZAWA MINORU
Publication year - 1987
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1987.tb04851.x
Subject(s) - borosilicate glass , materials science , composite material , annealing (glass) , soda lime glass , ultimate tensile strength , atmosphere (unit) , soda lime , kinetics , viscous flow , residual stress , silica glass , thermodynamics , mechanics , physics , quantum mechanics
When abraded or indented glasses are annealed, a strength increase of 20% to 30% is observed. Crack tip blunting and removal of tensile residual stress near the crack tip have both been proposed to explain this phenomenon. In order to resolve which is the more likely mechanism, the kinetics of strength increase of soda‐lime, borosilicate, and high‐silica glasses were measured as a function of heat‐treatment temperature and atmosphere. The sinusoidal profile decay of corrugated glass surfaces of the soda‐lime glass was also investigated at similar temperatures and atmospheres. From these two complementary measurements, it was concluded that the observed strength increase of glasses upon annealing is caused by crack tip blunting, most likely due to viscous flow assisted by water diffused from the atmosphere.