A STUDY OF STRESS CORROSION OF GLASS FIBERS.
Technical summary rept. 15 May 67-15 May 68,
SOLAR TURBINES INTERNATIONAL SAN DIEGO CA
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Tensile and static fatigue tests were made on E-glass filaments to determine the mechanism of stress corrosion that occurs in the presence of water vapor. Transmission electron microscopy and chemical analyses of the glass were used to provide supporting evidence. Mechanical tests in nominally sodium-free solutions in either sprayed or bulk forms showed no strength loss in alkaline solutions of pH 14, but progressively increasing strength loss as the pH was changed from 8 to 12. Sodium-containing solutions acted in a special manner that could be explained by a controlling chemical reaction SiONa H -- SiOH Na. In agreement with this ion exchange reaction, it was found that the strength of E-glass hydrolyzed by HCl solution could be restored by immersion in NaOH. Evidence is presented to show that phase separation occurs in E-glass filaments, with the approximate dimensions of 100A. A tentative theory is advanced to explain the mechanism of stress corrosion. Author
- Physical Chemistry
- Ceramics, Refractories and Glass