Glass strength/strengthening and flaws, indentation hardness and cracking (site sponsor, C.R.'Chuck' Kurkjian)

More research = Better understanding = Stronger Glass Collaboration is the Path to Progress
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On this page, I intend to periodically post my ideas for the improvement of the strength of glasses.  While these may occasionally (or perhaps always), seem off-the-wall, they are primarily meant to stimulate thinking on such issues.  They may be 'off-the-cuff' in some cases and I will welcome any and all comments.
 
1.  Ratio of shear to volume flow during indentation and scratching.
(posted 5 19 2009).
Recent works by Roxel and Yoshida and others (Koike, Kato....  ) have shown that changes in glass composition can lead to changes in the relative amounts of shear and volume flow (compaction) that occur during indentation and scratching.  Studies on the compaction of glasses (Bridgman, Mackenzie, Cohen, etc.) during the 1960's had showed that the amount of shear stress present during compaction had a very great effect on the amount of compaction that occurred.  Studies of the composition and indenter shape dependence of such behavior is therefore important.