VOL 86, No. 11 (2013)

The behavior of iron in the structure of sodium iron-containing borosilicate glasses with different ratios of network-forming cations and modifier cations was studied using the methods of M?ssbauer and vibrational spectroscopy. The difference in the distribution of modifier cations between different types of structural units in the structure of the initial and iron-containing sodium borosilicate glasses was established. With the addition of iron, the proportion of BO4 tetrahedra decreases and the BO3 triangles and the proportion of structural units Q ² and Q ³ increase, containing nonbridging oxygen atoms. This is accompanied by the destruction of mixed silicon borate rings and the formation of Si-O-Fe ³⁺ bridging bonds and Si-O- nonbridging bonds coordinated by Fe ²⁺ ions.

The focal length and numerical aperture of a modified region of a complex structure in the volume of a porous glass plate are estimated. It is shown that when sintering a porous glass plate with a modified region, the complex structure of the modified region is retained. An assessment of the focal length and numerical aperture of a modified region of a complex structure in a quartz-shaped glass plate is carried out. It was found that sintering a porous glass plate with a modified area in a furnace contributes to a significant decrease in the focal length and an increase in the numerical aperture to 0.9.

The optimal conditions for the synthesis of nanopowders partially stabilized by yttrium (molar fraction 3% Y ₂ O ₃) of zirconium dioxide by the glycine-nitrate method and the modes of obtaining high-strength ceramics from nanopowders by the method of semi-dry pressing and sintering have been found....

The effect of nanosized hydrosols and organoxogel of aluminum oxide on the properties of aqueous suspensions modified with nanosols of bentonite and refractory clays has been investigated. The dependence of the properties of modified bentonite and refractory compositions on the type of nanosol and the effect of an electromagnetic field was analyzed based on the change in the increment, fluidity of the slip, structure of the sol, shrinkage and strength of the fired samples.

The analysis of integral and local compaction during sintering of ceramic materials is carried out. A model is proposed that describes the structure of the material during sintering and takes into account the process of clustering of particles constituting the material. Formulas for micro- and macroporous space (coordination number, specific surface area and average pore size) and an algorithm for their calculation are obtained. The calculation according to the model showed that at the beginning of sintering the size of macropores sharply increases.

A method of solid-phase neutralization of effluents (when obtaining highly pure quartz) with dry quicklime in a moving layer of material has been investigated. The use of this method will make it possible to obtain a solid granular product at the exit from the apparatus of the granulator-neutralizer, which is convenient for subsequent processing (briquetting and drying for the needs of metallurgy or sending to a landfill). The advantages of this method over the liquid phase are the exclusion from the technological scheme of operations for the preparation of milk of lime and the filtration of fine sediment, a significant reduction in the volume of waste water, and the production of flux in granular form.

A method has been developed for the formation of glass-ceramic coatings on bioinert substrates directly from an organic solution, which makes it possible to create thin bioactive layers on porous materials that repeat the shape of the pores of the carrier. The method of obtaining bioglass of various compositions from organic solutions has advantages over the method of obtaining from aqueous solutions: it avoids fractional crystallization during evaporation, as well as before the sol-gel method: it makes it easier to penetrate into the pores of bioinert carriers and form multilayer coatings.

Protective technological coatings have been developed that combine the advantages of the method of non-oxidative heating of metal and high-temperature technological lubricants and heat-insulating coatings. The efficiency of using a polyfunctional protective technological coating on superheat-resistant nickel alloys is shown.