Access

You are not currently logged in.

Access JSTOR through your library or other institution:

login

Log in through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Journal Article

Detection of Strength-Impairing Surface Flaws in Glass

F. M. Ernsberger
Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences
Vol. 257, No. 1289 (Sep. 6, 1960), pp. 213-223
Published by: Royal Society
Stable URL: http://www.jstor.org/stable/2413811
Page Count: 15
Were these topics helpful?
See something inaccurate? Let us know!

Select the topics that are inaccurate.

Cancel
  • Read Online (Free)
  • Add to My Lists
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Detection of Strength-Impairing Surface Flaws in Glass
Preview not available

Abstract

Experiments have shown that the cracks produced by sodium vapour treatment on the surface of glass (Andrade & Tsien 1937) are fractures due to a superficial tensile stress developed on cooling in a surface layer of higher thermal expansion. Tensile surface stresses and corresponding systems of cracks can also be developed, in soda-lime glass, by treatment with a molten lithium salt. The points of origin of the crack systems can be clearly recognized; they must be the sites of Griffith cracks. The structure (linear or star-like) of each Griffith crack can be recognized from the orientation of the network cracks at the point in question. The experimental evidence for the present interpretation of the Andrade-Tsien cracks is as follows: (1) A large amount of sodium is absorbed in the surface layer of the glass. (2) The characteristic crack patterns are not visible at the end of the heating period in sodium vapour, but appear progressively as the sodium-treated glass cools. (3) The cracks disappear when the glass is reheated, and a new pattern appears on subsequent cooling.

Page Thumbnails

  • Thumbnail: Page 
213
    213
  • Thumbnail: Page 
214
    214
  • Thumbnail: Page 
215
    215
  • Thumbnail: Page 
216
    216
  • Thumbnail: Page 
217
    217
  • Thumbnail: Page 
218
    218
  • Thumbnail: Page 
[unnumbered]
    [unnumbered]
  • Thumbnail: Page 
[unnumbered]
    [unnumbered]
  • Thumbnail: Page 
[unnumbered]
    [unnumbered]
  • Thumbnail: Page 
[unnumbered]
    [unnumbered]
  • Thumbnail: Page 
219
    219
  • Thumbnail: Page 
220
    220
  • Thumbnail: Page 
221
    221
  • Thumbnail: Page 
222
    222
  • Thumbnail: Page 
223
    223