VOL 81, No. 4 (2008)

The process of clarification of alkali-free glass type E (production of glass beads and continuous glass fibers) with sodium sulfate in comparison with antimony anhydride and cerium dioxide has been investigated. The high efficiency of sulfate clarification is shown and the technological parameters of its use are determined. Tab. 1, ill. 2, bibliography: 7 titles.

It has been established by calculation and experimental methods that the use of lithium metaphosphate for the preparation of charges of multi-lithium glasses of the Li ₂ O - Li ₂ SO ₄ - P ₂ O ₅ allows to reduce the temperature and time parameters of their cooking while increasing the homogeneity of the melts. Tab. 1, ill. 3, bibliography: 10 titles.

The influence of modifying additives on the sintering process, control of the microstructure and properties of ceramics is shown. The types of additives with different character of interaction with the crystal lattice of the basic oxide during sintering are considered. The most effective additives that significantly affect the sintering process and the formation of the microstructure are oxides that form solid solutions. Tab. 1, bibliography: 11 titles.

The effect of ultrasonic treatment on the rheological behavior of dispersed oxide - thermoplastic bond systems has been studied. The possibility of regulating the characteristics of thermoplastic slips by changing the duration of ultrasonic treatment is shown. Tab. 2, ill. 2, bibliography: 4 titles.

The process of nitriding of commercial FS 65 alloy in the mode of self-propagating high-temperature synthesis has been studied. The influence of the phase composition of the initial alloy on the combustion process has been established. The dependence of the degree of nitriding of combustion products on nitrogen pressure, sample diameter, and dilution of the initial charge with inert and activating additives has been studied. Silicon nitride with a residual iron content of 0.07% was obtained by acid enrichment. Il. 6, bibliography: 3 titles.

The properties of optically transparent ceramic materials based on yttrium oxide and yttrium-aluminum garnet are analyzed. It has been shown that it is promising to manufacture transparent ceramics combining both of these compounds. Methods for the synthesis of yttrium oxide and yttrium-aluminum garnet are considered. The choice of the synthesis method is substantiated. The possibility of creating such materials without introducing modifying additives has been confirmed. Bibliography: 17 titles.

The properties of hydroxyapatite powder synthesized from calcium acetate, hydrogen phosphate, and potassium hydroxide have been investigated. A by-product of the reaction (SPR), the main component of which is potassium acetate, modifies the surface of hydroxyapatite nanocrystallites. The SPR components can play the role of a salt matrix, preventing the fusion of nanocrystallites, and can also serve as a source of a sintering additive, the uniform distribution of which occurs due to adsorption during synthesis. Thanks to the introduction of a sintering additive in the form of a SPR at a temperature of 700 ° C, a hydroxyapatite-based ceramic with a homogeneous microstructure and a grain size of no more than 300 nm was obtained. SPR is the reason for the occurrence of various solid-phase processes and processes with the participation of the liquid phase. The place of occurrence of such processes is the grain boundaries, which inhibits their growth. Tab. 1, ill. 7, bibliography: 6 titles.

In terms of thermal insulation properties and environmental friendliness during production and operation, foam glass is one of the most demanded materials. There is a tendency towards the development of foam glass production in Russia. In the coming years, at least six lines for the production of foam glass will be put into operation. Tab. 3, bibliography: 2 titles.

The capabilities of X-ray spectral devices for express analysis of raw materials, as well as glass and ceramics are shown. The range of the content of the determined elements in the sample is from 1 ppm (million ^-1) to 100%. Measurement duration 10 - 15 s. Tab. 3, ill. 3.