The results of an X-ray study of iron aluminate with a unit cell parameter a = 8.090 (4) & Aring; and cation-defective iron aluminate Fe 0.5 Al 2.33 O 4 with a = 8.002 & Aring; as well as a new modification of aluminum oxide synthesized by impact of explosives containing aluminum. Aluminum oxide can crystallize in a hexagonal system in a primitive lattice with a = 9.151 (1) & Aring ;, c = 7.945 (2) & Aring ;, V = 576 & Aring; 3 or in tetragonal in a primitive lattice with twice smaller volume - a = 7.941 (2) & Aring ;, c = 4.575 (1) & Aring ;, V = 288 & Aring; 3 . Tab. 5, ill. 3, bibliography: 30 titles.
The results of studies to determine the possibility of using local raw materials of Uzbekistan for the production of electrical ceramics are presented. The properties of ceramics are studied depending on the chemical composition of pegmatites of various deposits. It was determined that the electrical characteristics primarily depend on the content of oxides of alkaline elements in porcelain and, to a lesser extent, on the K 2 O: Na 2 O ratio in silica-containing raw materials. Tab. 3, bibliography: 3 titles.
Based on the results of calculations of the enthalpy of formation of beryllium oxide doped with titanium, obtained using quantum-chemical calculations within the framework of the DFT theory, the limit of solubility of titanium in BeO was estimated. Using the example of titanium-doped beryllium oxide, a technique for the numerical estimation of the limit of solubility of impurities in crystals is considered, based on the use of the results of ab initio quantum-chemical calculations. The technique can be used to assess the solubility limit of various impurities in inorganic compounds and ceramic materials based on them. Il. 1, bibliography: 7 titles.
The properties of the powder synthesized from calcium nitrate and ammonium hydrogen phosphate in the presence of polyvinyl alcohol have been investigated. It was found that the presence of PVA in an amount of 0.25 - 0.50% significantly affects the rheological and thermal properties of the powder. The microstructure of ceramics based on hydroxyapatite synthesized with PVA shows a tendency towards abnormal grain growth. Tab. 1, ill. 7, bibliography: 15 titles.
A technology for producing porcelain stoneware from natural materials of Uzbekistan has been developed. Investigations of the processes occurring during the heat treatment of porcelain stones from the Boynaksay deposit have been carried out. The optimal firing temperature, the composition of the ceramic mass, as well as the influence of individual components of the charge on the properties of porcelain stoneware have been determined. The kinetics of sintering of experimental masses has been studied. It is shown that by combining various types of mineral raw materials, it is possible to obtain porcelain stoneware with high thermomechanical characteristics. Tab. 3, ill. 1, bibliography: 3 titles.
The effect of ultrasound on the deformation properties of thermoplastic slips has been studied. It is shown that, upon sonication, the change in the plastic strength of casting systems beryllium oxide - thermoplastic bond in the technological temperature range (40 - 55 ° C) is due to the effects of cavitation and dissipative heat release and can be characterized using the equation of the thermal activation process. Il. 4, bibliography: 8 titles.
The possibility of using local raw materials of Uzbekistan for obtaining acid-resistant materials has been determined. Compositions of masses based on porcelain stones from the Boinaksay deposit and pyroxene waste from the Koitash ore field have been developed. It is shown that, using non-traditional mineral raw materials, the mineral composition of which is close to the compositions of standard fine-ceramic masses, it is possible to obtain ceramic materials with good thermomechanical and chemical properties. Tab. 2, ill. 1, bibliography: 8 titles.
The processes of synthesis of ceramic pigments at equimolecular ratios of oxides (Nd 2 O 3 : P 2 O 5 , Nd < sub> 2 O 3 : ZrO 2 , Nd 2 O 3 : TiO 2 ). It is shown that such ratios of oxides make it possible to obtain pigments of different palettes suitable for coloring glazes. Tab. 1, ill. 2, bibliography: 3 titles.
The use of unconventional electrolyte DULAPIX Ca in the process of liquefaction of the majolica mass allows to reduce the moisture content of the slip. The degree of moisture reduction in the slip depends on the hardness of the water: the higher its hardness, the higher the electrolyte content in the slip. Therefore, in the production of majolica slip, it is necessary to control the water hardness and use softened water. Tab. 1, ill. 1.
The results of a study of the possibility of volumetric coloring of ceramic bricks by introducing manganese and iron ores, as well as metallurgical slags and sludge from electroplating industries, are presented. It was found that in order to achieve an expanded color range of products, it is advisable to pre-bleach low-melting clays with chalk or refractory clay, kaolin, impregnated with solutions of transition metal salts. The use of natural raw materials and soluble salts of 3d elements will significantly expand the raw material base, reduce the cost of ceramic products by replacing expensive materials, as well as combining the processes of pigment synthesis and firing products. Tab. 2, ill. 2, bibliography: 7 titles.
