VOL 76, No. 12 (2003)

An algorithm for calculating the wave-like deformation of sheet glass under horizontal hardening conditions, which is fundamentally different from those developed earlier, is presented. The calculation of the minimum speed of glass transportation corresponding to its maximum permissible deformation has been carried out. The algorithm is recommended to be used when designing horizontal glass tempering lines. Il. 2, bibliography: 4 titles.

Using the example of industrial silicate optical crowns, the ability of glass melts of different composition to be clarified with arsenic and antimony oxides has been studied. It was found that the kinetics of the decomposition reaction of arsenic pentoxide, which is responsible for the removal of bubbles from the molten glass, is closely related to the redox potential of the melt. Practical recommendations are given. Tab. 4, bibliography: 7 titles.

The results of the synthesis by the sol-gel technology in an aqueous medium of a sodium silicate mixture for the manufacture of microspheres are presented. It was proved that without high-temperature treatment, crystalline phases were formed, which are marked on the Krachek diagram. A nomogram has been developed, which is recommended for use in glass design for modeling the phase composition for a given silicate modulus and structure connectivity factor, taking into account the influence of Na ₂ O and SiO ₂ on the properties of glass, as well as to determine the area of ??probable glass formation and to optimize the technological process. Tab. 1, ill. 3, bibliography: 8 titles.

The possibility of using self-propagating crystallization, accompanied by the propagation of the front of a thermal crystallization wave, during the transition of foam silicate obtained on the basis of the compositions of the CaO - MgO - Al ₂ O ₃ - SiO _{2 system} by the method of reduction melting with the separation of the melt and subsequent cooling of the silicate part in the thermal shock mode, from the X-ray amorphous state to the crystalline state. The characteristics of the heat wave are given, the dependence of the speed of propagation of the heat wave on the dispersion of the foam silicate and the molding pressure of the products is established. Tab. 1, ill. 3, bibliography: 6 titles.

An explanation is proposed for the possibility of the formation of solid solutions of silicon oxide in mullite. The difference in the diffusion coefficients of cations in complex oxides during their synthesis leads to the formation of a solid solution of an oxide containing a cation with a lower diffusion coefficient in a complex oxide and a phase consisting of an oxide containing a cation with a high diffusion coefficient or enriched in this oxide. Using additives of yttrium or scandium oxides, which are chemisorbed onto the aerosil surface (source of SiO ₂), it is possible to make the rate of diffusion mass transfer of aluminum cations higher than that of silicon cations, and to obtain a solid solution of silicon oxide in mullite. Il. 2, bibliography: 10 titles.

The author's many years of experience in the field of ceramic pressing technology are summarized, which can be used by specialists both for the restoration and improvement of technological processes for the production of ceramics at enterprises, and for improving the quality of products. Il. 2, bibliography: 5 titles.

A technology for the production of gypsum-ceramic material based on fluoroanhydrite has been developed. With the help of methods of physicochemical analysis, its composition and properties are determined. The developed material is ground and polished, does not accumulate static electricity, and has a surface texture similar to marble. Il. 6, bibliography: 2 titles.

Within the framework of a quasi-static uncoupled problem of thermoelasticity, one-sided heating of a glass or ceramic plate freely clamped along the contour by a surface source is considered. An analytical relationship is obtained, which is a criterion for the thermal strength of a plate and allows one to determine non-destructive processing modes. It is shown that for many materials there is a region of variation of the Fourier number, in which the destruction of the processed plate by thermoelastic stresses is possible. Il. 1, bibliography: 10 titles.

The fundamental possibility of using natural soda for partial replacement of traditional soda-containing raw materials in the technology of sheet and other types of glass has been established. The physicochemical characteristics of natural soda and the features of its behavior at the stage of preparation of the charge by the granulation method were investigated, which made it possible to determine the optimal conditions for its preparation. Tab. 3, ill. 3, bibliography: 3 titles.