APPLICATION OF INFRARED SPECTROSCOPY FOR THE DETERMINATION OF STRUCTURAL CHANGES AT ION-EXCHANGE HARDENING OF GLASSES,
Abstract
To check on the ion exchange method of glass strengthening, the authors treated samples of sodium-aluminum-silicate glasses to which TiO2 was added. The ion exchange was produced in a salt bath containing 95 wt.% Li2SO4 and 5 wt.% Na2SO4. Treatment of the glass for several minutes at 830-900C resulted in an increase in strength by 6-10 times, owing to the crystallization of beta-eucryptite which has a negative coefficient of thermal expansion on the surface. The thickness of this pyroceramic layer was determined by infrared spectroscopy, based on the fact that the spectrum of light reflected from the surface differs from the spectrum of the untreated glass inside the sample. The thickness increases with the treatment time from 50-55 microns at three minutes to 90-110 microns. The depth of the ion-exchange layer increases in proportion to the square root of the treatment time, thus showing that the ion exchange is governed by diffusion processes. The infrared spectroscopy results agreed with measurements made with a microscope. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 25, 1968
- Accession Number
- AD0685137
Entities
People
- K. K. Evstropev
- O. V. Zhukovskaya
- V. K. Pavlovskii
Organizations
- National Air and Space Intelligence Center