VOL 72, No. 11 (1999)

Based on the results of measuring the x-potential of hydrated quartz glass particles, the number of mechanically and thermally dangling chemical bonds Si-O-Si per unit surface area of ??quartz glass, which are the source of the manifestation of the electrosurface properties of particles, is estimated. Il. 3, bibliography: 4 titles.

A method for the structural interpretation of the concentration dependences of the properties of two-component silicate glasses (by the example of their molar volume) is considered, based on the establishment of a correlation between the values ??of a certain property and the degree of depolymerization of the silicon-oxygen framework (structural network) of the glass R, which reflects the number of non-bridging oxygen per one silicon-oxygen tetrahedron.... The partial values ??of the molar volume of a number of oxides of the first and second groups of the periodic system, which retain their constant values ??in the entire region of glass formation, have been determined. The error in calculating the molar volume of glasses by the proposed method is ~ 1%. Tab. 2, ill. 3, bibliography: 15 titles.

The influence of a set of versatile operating factors on the redox equilibrium of iron in glass and the thermal transparency of the molten glass under conditions of a continuous technological process of sheet glass production is considered. Table 1, bibliography: 5 titles.

By the method of electron paramagnetic resonance of beryllium ceramics with impurities B ³⁺, Al ³⁺, Zn ²⁺, Li ⁺ and REE obtained by slip casting, semi-dry and high-temperature pressing, point defects and possible reasons for their formation were investigated. A number of impurity centers have been identified that determine the optical, luminescent, diffusion, and other physicochemical properties of beryllium ceramics. Tab. 2, bibliography: 12 titles.

The features of the processes of phase formation and formation of the structure of materials based on Al ₂ O ₃, ZrO ₂, and SiO ₂ have been established. The fundamental possibility of using such materials for the protection of various structural materials from gas corrosion at high temperatures is shown. Tab. 1, ill. 1, bibliography: 3 titles.

The influence of imperfections in the crystal lattice of tungsten trioxide, caused by the violation of its stoichiometry, on polymorphic transitions arising with a change in temperature is considered. It is shown that the introduction of a more electropositive metal into tungsten trioxide, which converts this oxide into oxide-tungsten bronze, leads to the suppression of the phenomena of oxygen nonstoichiometry, which creates conditions for the stabilization of polymorphic modifications in a wide temperature range. Tab. 1, ill. 4, bibliography: 16 titles.

The analysis of different types of enamels for steel and cast iron is given. Their chemical compositions and basic physical and mechanical properties are given. The current state of scientific research on synthesizing new types of enamels and improving the physical and mechanical properties of traditional glass enamels is considered. The possibilities of replacing expensive raw material components of enamels with less expensive and non-scarce raw materials, as well as the use of secondary waste, are shown. Tab. 2, bibliography: 29 titles.

The effect of the structure (type of pores, their size, fiber diameter) of highly dispersed porous materials on their thermal conductivity is considered. Tab. 1, ill. 3, bibliography: 10 titles.