VOL 84, No. 12 (2011)

Glass formation, crystallization ability, physicochemical properties, and spectral characteristics of glasses of the GeO ₂ - TeO ₂ - B ₂ O _{3 - PbO. The structural features of glasses are investigated and the coordination transitions of boron and germanium ions in their structure are revealed. A nonlinear dependence of the physicochemical properties of glasses on their composition and structure, interpreted by the manifestation of "borate and germanate" anomalies in glasses, has been established. Optical absorption spectra of glasses are characterized by a steep fundamental absorption edge at the border of the visible and UV regions of the spectrum, which allows them to be recommended for use as light filters that cut off the UV region. Il. 5, bibliography: 14 titles.}

The problem of manufacturing a quartz glass cell by welding with CO ₂ lasers is being solved. Thermophysical analysis of the process was carried out and its mathematical model was drawn up. Welding was carried out in two ways - overlap and T-seam. In both cases, the optimization of laser radiation parameters for welding quartz plates was performed. Il. 7, bibliography: 4 titles.

The spectrocolorimetric and luminescent characteristics of porcelain containing neodymium oxide additives have been studied. It has been shown that an increase in whiteness occurs when the content of neodymium oxide is low, and when it is increased, the coloration process begins. The increase in the whiteness of porcelain is explained by a combination of two optical effects: an increase in reflection in the blue-blue region of the visible spectrum, due to the appearance of sensitizing luminescence of the neodymium ion in the region of 390 - 480 nm and a decrease in yellowness associated with the absorption of the neodymium ion in the range of 560 - 590 nm and a shift in the reflection maximum into the blue-green region of the spectrum. Tab. 1, ill. 7, bibliography: 12 titles.

The development of crystalline phases (mullite, pseudo-cubic zirconium dioxide, and zircon), microstructure, linear shrinkage, apparent density, and compressive strength of ceramic samples obtained from powders after grinding and synthesis in a reactor using illite clay as a binding agent in depending on the temperature regime during spark plasma sintering. The results of X-ray phase analysis indicate an intensive development of the mullite phase and pseudocubic zirconia in all samples with an increase in the sintering temperature, and the formation of a dense microstructure of the samples is also observed. Additionally, the linear shrinkage of the samples increases with an increase in the sintering temperature, as well as the apparent density and compressive strength of the samples with an increase in the grinding time up to 24 h and the introduction of clay into the samples, showing, respectively, the maximum values ??of 3.45 g / cm ^{3 and 252.0 MPa. Il. 7, bibliography: 19 titles.}

The features of obtaining polydisperse dry compositions for slip enameling of low-carbon steels are considered. The effect of a deflocculating additive - xanthan gum on the technological and rheological properties of slips, as well as on the quality of the coating - has been investigated.

High-temperature interactions between calcium and strontium titanodisilicates have been investigated. The formation of two limited series of tetragonal solid solutions based on these initial compounds was established. The discontinuous nature of changes in the physicochemical properties of solid solutions, depending on the composition, has been determined. Glasses and glass-crystalline materials based on the studied system Ca ₂ TiSi ₂ O ₈ - Sr ₂ TiSi ₂ O ₈, and the characteristic features of glass crystallization and the temperature limits of the existence of the crystalline phase have been elucidated. Tab. 1, ill. 2, bibliography: 5 titles.

The analysis of physical and technical indicators, chemical and mineralogical compositions of pyrophyllite rocks of the Kul-Yurt-Tau deposit of the Republic of Bashkortostan in terms of their use as the main component of refractory composites on a phosphate binder is carried out. The characteristics of the pyrophyllite mineral and the rocks of the indicated deposit are considered. Based on the information received, the initial materials for research were selected. Tab. 2, ill. 1, bibliography: 14 titles.