Accession Number:

AD0767920

Title:

Investigation of Viscous Flow in Glass During Phase Separation.

Descriptive Note:

Annual rept. no. 1, Nov 72-Jun 73,

Corporate Author:

NATIONAL BUREAU OF STANDARDS GAITHERSBURG MD

Report Date:

1973-09-01

Pagination or Media Count:

42.0

Abstract:

The isothermal viscosity of two borosilicate glasses, of which one is a commercial glass widely used for chemical glassware, shows a large increase 4 to 5 orders of magnitude with heat-treatment time ranging up to 100,000 min near the annealing point. The two glasses have similar compositions, but differ greatly in their phase separation characteristics. Electron micrographs are used to analyze the development of microstructure during the suspected phase separation. In both glasses, it is found that the structure development is primarily responsible for the viscosity increase. An analysis of the data, and a theoretical interpretation of the effect are presented. Author

Subject Categories:

  • Physical Chemistry
  • Ceramics, Refractories and Glass

Distribution Statement:

APPROVED FOR PUBLIC RELEASE