Premium
Measurement of the silica glass fatigue limit
Author(s) -
Aaldenberg Jared S.,
Lezzi Peter J.
Publication year - 2020
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/jace.16970
Subject(s) - materials science , composite material , cantilever , paris' law , fatigue limit , stress intensity factor , relaxation (psychology) , stress (linguistics) , crack closure , analytical chemistry (journal) , fracture mechanics , chemistry , psychology , social psychology , linguistics , philosophy , chromatography
The static fatigue limit, or the threshold stress intensity factor, K o , for first subcritical crack growth has been measured directly in silica glass for T ≥ 600°C using the double cantilever beam (DCB) crack growth technique. Values measured ranged from 0.48 to 0.61 MPa·m 1/2 for a temperature range of 600°C‐850°C, respectively. Cracks growing near the static fatigue limit had a time‐dependence, where the crack growth decreased and appeared to stop at K ≈ K o . Slow crack growth curves ( K ‐ v ) have been measured from room temperature, 50% RH, up to 850°C with subcritical crack growth not measurable for T > 900°C. Increasing temperature was found to first increase, and then decrease the slope of Region I, and a peak in fatigue resistance was found around 150°C‐300°C. At T > 600°C subcritical crack growth was observed for K higher than previously measured K IC values. This observation and the static fatigue limit in silica are explained by a water‐assisted stress relaxation mechanism at the crack tip.