VOL 84, No. 2 (2011)

The formation of the equilibrium Cr (III) & hArr; Cr (VI) in colored optical glasses under the combined action of the acid-base properties of the matrix, the total concentration of chromium and the amount of other elements of variable valence located in the redox series to the right of chromium, and the relationship of this equilibrium with the change in the spectral characteristics of the glass is shown. Tab. 5, ill. 3, bibliography: 7 titles.

A method for preliminary briquetting of a foam glass charge using water as a technological binder is considered. The operating parameters of the preparation of the foam glass mixture have been determined. It has been established that hydration and hydrolysis of glass contribute to the improvement of the conditions for swelling of foam glass and an increase in its physical and technical parameters. Il. 3, bibliography: 4 titles.

Glasses of composition (in moles) 2Bi ₂ O ₃, 3GeO ₂ were obtained. Glasses have different colors and differ in electrical properties. This is due to the different concentration of bismuth ions with an oxidation state other than +3. The characteristic temperatures of these glasses were determined, based on which the modes of heat treatment were selected in order to obtain transparent glass ceramics. The influence of glass melting modes on the glass crystallization process has been established. Some physicochemical properties of the obtained glass ceramics have been investigated. Tab. 3, ill. 6, bibliography: 9 titles.

The features of the structure of porcelain items, which were molded by the pouring and pouring method of slip casting, have been determined. The possibility of identifying the method of manufacturing products has been established. The data obtained can be useful for determining the mechanism of defects in porcelain produced by casting. Tab. 2, ill. 7, bibliography. 3 titles

The influence of colemanite additives on sintering, properties and microstructure of spodumene ceramics has been investigated. It has been established that the introduction of colemanite in an amount of 5-7% is most effective for intensifying sintering processes and forming a denser ceramic structure. Received spodumene ceramics with TCLE (9.8... 12.9) & sdot; 10 ^-7 К ^-1, heat resistance more than 100 thermal cycles (800 ° С - water), water absorption 0.7 - 5.0% and mechanical strength in bending 33 - 44 MPa, provided at a firing temperature of 1200 ° C. Il. 4, bibliography: 8 titles.

A method of obtaining yttrium-stabilized zirconium ceramics by cold isostatic pressing without using a binder from zirconium dioxide nanopowder obtained by the method of reverse coprecipitation is considered. The main characteristics of the powder have been determined by X-ray diffraction, BET, thermal analysis, transmission and atomic force microscopy. It was found that the Zr _0.92 Y _0.08 O ₂ powder consists of a pure tetragonal phase with a particle size of 10 nm. The microstructure and composition of zirconium ceramics were studied by SEM and XRD methods. The data obtained on the transition of the tetragonal phase of zirconium ceramics to the monoclinic phase with an increase in the sintering temperature are associated with the growth of the ceramic grain at high temperatures. Il. 5, bibliography: 4 titles.

The possibility of obtaining heat-resistant coatings on chamotte refractories by the method of self-propagating high-temperature synthesis in the MgO - SiO ₂ - Al system with the use of liquid sodium glass as a binder with the addition of sodium tripolyphosphate and an additive activating the SHS process, titanium dioxide, has been investigated. The optimal composition has been determined, the physical and mechanical properties, macro- and microstructure of the coatings have been investigated. Il. 4, bibliography: 17 titles.