A study of the effect of the ion exchange strengthening method on macroflaws in sodalime glass
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Authors
Burcham, William Richard
Subjects
Advisors
von Schwind, J.J.
Leonesio, Robert B.
Date of Issue
1972-03
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
This work examines the strengthening effect of the ion exchange
method of chemical tempering on two specific types of macroflaws, a
thermally blunted crack and a sawcut, in soda-lime glass. The use of
these macroflaws permitted a quantitative fracture mechanics analysis
of the amount of strengthening produced, and a greater access for ion
exchange at the flaw tip than could be afforded by a sharp crack. The
specimens were treated for various lengths of time in a potassium
nitrate bath at 365°C. A double cantilever cleavage technique of
measuring fracture surface energy was used to find G , the strain energy
release rate. The average increase in G was found to be roughly linear
reaching a maximum level of approximately 200% at twelve hours of
treatment for the blunted crack specimen type, while a similar maximum
of approximately 200% was reached at six hours of treatment for the
sawcut specimen type.
Type
Thesis
Description
Series/Report No
Department
Oceanography
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
Funding
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.