On the example of type E borosilicate glass, an assessment is given of the possibility of replacing boric acid in the batch composition of glass with colemanite. The processes occurring during glass melting at the stages of silicate and glass formation are considered. The influence of colemanite on the indicated processes has been studied. Tab. 1, ill. 4, bibliography: 3 titles.
A method is proposed for calculating the composition dependence of various properties of three-component alkali-silicate glasses of the Na 2 O - K 2 O - SiO 2 and Li systems 2 O - K 2 O - SiO 2 , one of the components of which is the homogenizing alkaline oxide K 2 O. As parameters in the calculation formula, the dependence of the corresponding properties on the content of alkali oxide in two-component alkali-silicate glasses is used: Li 2 O - SiO 2 , Na 2 O - SiO 2 and K 2 O - SiO 2 . Comparison of the calculated and experimental data for density and refraction testifies in favor of the provisions that form the basis of the proposed model. Tab. 1, ill. 2, bibliography: 6 titles.
The main provisions of rheology are stated. The main rheological characteristics during flow and some structural features of silicate glass-forming melts are presented. The features of the change in the deformation characteristics of molten glass during the industrial molding of glass products, in particular glass containers, are reflected. Il. 4, bibliography: 8 titles.
It has been established by X-ray diffraction and electron microscopy that in glasses of the La 2 O 3 - B 2 O 3 - GeO 2 a film texture of lanthanum germanate La 2 Ge 2 O < sub> 7 with a thickness of up to 5 ?m, under which a needle-shaped texture of the stillwellite-like LaBGeO 5 with pyroelectric properties is formed. The temperature dependences of the dielectric and pyroelectric properties of samples with a sandwich structure La 2 Ge 2 O 7 - LaBGeO 5 - La 2 Ge 2 O 7 and polished samples containing only the stillwellite-like phase. Il. 9, bibliography: 12 titles.
The influence of the intensity of air cooling on the heat transfer through the electrofused AZS-bar of the side wall of the cooking basin has been investigated. The expediency of using air cooling during the entire furnace campaign is shown. Tab. 1, ill. 2, bibliography: 10 titles.
The possibilities of evaluating the quality of the surface treatment of optical glass during grinding and polishing have been investigated. Tab. 1, ill. 3, bibliography: 4 titles.
Glasses of compositions (100 - x) KNbO 3 - xSiO 2 (x = 12 - 35) were obtained, which, upon heat treatment in the region of glass transition temperatures, form a transparent glass ceramics. The initial stages of phase separation are accompanied by the appearance of a noticeable quadratic optical nonlinearity in glasses, which can be used to create highly efficient electro-optical modulators by thermal poling methods. Il. 4, bibliography: 12 titles.
The proposed method was used to determine the values ??of the viscosity of glass and glass-crystalline compositions in the temperature range of foaming. It was found that when the glass-crystalline composition contains less than 75% of the glass phase, its viscosity depends on the ratio of the crystalline and glassy phases, with the content of more than 75% - the viscosity of the composition and the coefficient of foaming are determined mainly by the composition of the glass phase. Tab. 2, ill. 3, bibliography: 5 titles.
Silicate glasses with additives of cerium and titanium oxides, which are of interest for the manufacture of incandescent lamps for automobile headlights and thermostable light filters, have been investigated. It was found that the appearance of a characteristic yellow-orange coloration is due to the formation of chromophore centers, which include the product of the interaction of cerium and titanium oxides. Based on the measurement of optical transmission, photoluminescence, and XPS data for the composition used for the manufacture of light filters, it is assumed that titanium is predominantly in the form of Ti 4+ ions, and cerium - in two states: Ce 3+ < / sup> and Ce 4+ . Tab. 1, ill. 3, bibliography: 18 titles.
The physicomechanical properties of mineral fibers made from volcanic slags from two deposits in Armenia have been studied. It is shown that slag fibers can become an alternative to widely used glass fibers. Their modulus of elasticity coincides with that of glass fibers of composition S, strength is close to that of glass fibers of composition E. The elastic strength characteristics of composites exceed the corresponding indicators of materials based on basalt and andesitodacite fibers. Tab. 6, ill. 3, bibliography: 2 titles.
