VOL 81, No. 2 (2008)

It is shown that the structural features of quartz glasses make it possible to use the Herring model to describe their viscous flow, and the uneven distribution of impurities explains the known regularities in the dependence of the viscosity coefficient on their content. Bibliography: 12 titles.

It is shown that the transparency of the substrate significantly affects the light transmission of glass products modified with sol-gel coatings. In contrast to glass, where light scattering is proportional to the refractive index, an inversely proportional relationship was found in the studied films, which can be explained by the effect of porosity on a decrease in the refractive index of the coating. Tab. 1, ill. 3, bibliography: 7 titles.

Various methods of manufacturing highly dispersed oxide powders and their compounds, which are used to obtain dense and durable ceramic materials with an adjustable microstructure, are considered. The most common chemical methods for producing highly dispersed powders, providing an even distribution of components. The use of the method of heterophase deposition makes it possible to obtain X-ray amorphous hydroxide powders, which are well filtered with a spherical aggregate size of 0.5 ?m or less. When calcined, the structure of hydroxides is transferred to the resulting oxides, from which high quality ceramic products are made. Tab. 1, ill. 1, bibliography: 14 titles.

The process of nitride formation during combustion in gaseous nitrogen of an iron-silicon alloy with additions of zircon concentrate has been investigated. It was found that the combustion of ferrosilicon in the presence of zircon (5 - 70%) is carried out in the surface mode, and the combustion products are multiphase. With optimal synthesis parameters (nitrogen pressure 4 - 7 MPa, sample diameter 35 - 40 mm), the combustion products are a composition consisting of a ceramic component (Si ₃ N ₄ - ZrO ₂ -Si ₂ N ₂ O) and iron (& # 945; -Fe). A composite ceramic powder with a mass content of iron of 0.5% was obtained by the acid enrichment method. Tab. 1, ill. 3, bibliography: 5 titles.

The relationship between the corrosiveness of enamel melts containing a complex adhesion activator, their electrical conductivity and adhesion strength of the corresponding coatings has been investigated. The partial and integral influence of oxides of variable valence on the indicated properties of ground glass enamels has been established. The provisions of the electrochemical theory of adhesion of enamel coatings to steel using a complex adhesion activator have been confirmed. Il. 3, bibliography: 6 titles.

The possibility of obtaining white enamel for steel with a cooking temperature of 1000 - 1100 ° C and a firing temperature of 750 - 780 ° C and white enamel for aluminum with a cooking temperature of 900 - 950 ° C and a firing temperature of 530 - 560 ° C has been investigated. The physical and technological characteristics of the welded frits have been measured, and the temperature-time regimes of firing during slip enamel application have been determined. It has been established that the introduction of modifier oxides and glass-forming oxides allows, without introducing new components into the enamel, to reduce the cooking temperature by 15 - 20%, and the enamel firing temperature - by 20 - 30 ° C. Tab. 2, bibliography: 1 title.

The possibilities of obtaining pigments with the structure "inorganic core in a ferromagnetic shell" by the method of deposition of nickel and copper ferrites on the surface of microgranules of optical glass waste have been studied. The porous characteristics, physicochemical properties and surface structure of the synthesized pigments have been investigated. Tab. 2, ill. 6, bibliography: 8 titles.

It is shown that the reason for the formation of a strip of gas bubbles in the weld seam is the reversible oxidation of barium oxide in the temperature range of 300 - 600 ° C. To prevent the negative consequences of this process during welding of the glass of the flask and the cylinder of the electronic input, it is necessary to quickly heat the glass of the flask to a temperature of 700 - 730 ° C and carry out the welding at a temperature exceeding the upper oxidation temperature of barium oxide. Tab. 1, ill. 1, bibliography: 5 titles.

The most widespread deposits of diatomite in the world and in Russia are given. Areas of application of diatomite, properties of heat-insulating diatomite bricks are described. Il. 1, tab. 2, bibliography: 5 titles.