The results of a study of the possibility of synthesizing pigments of a corundum-spinel structure are presented, methods of directed regulation of the processes of structure and phase formation for obtaining pigments with high physicochemical characteristics have been developed. The relationship between the temperature-time parameters of the synthesis, the content of the introduced additives of oxides-modifiers and mineralizers with the type and amount of forming color-bearing phases, providing a rich color and a wide range of colors of pigments, has been established. Il. 3, bibliography: 4 titles.
The deformation behavior of porcelain and semi-porcelain specimens during firing under various types of loading is investigated: bending, tension, torsion. The dependences of the effective viscosity of materials on temperature have been calculated. The simplest way to determine deformation stability is bending of cantilevered specimens, the most informative and accurate is the torsion of thin-walled tubes. Il. 4, bibliography: 9 titles.
The results of experimental studies of the process of self-propagating high-temperature synthesis (SHS method) of blue-green nickel-containing spinels are presented. The composition of the compounds was confirmed by IR-spectroscopic, X-ray phase, metallographic and X-ray microanalysis analyzes. The influence of the composition of the charge on the structure and phase composition of the obtained compounds is shown. The SHS method makes it possible to obtain spinels, which can be used as high-temperature ceramic pigments.
Il. 3, bibliography: 4 titles.
The use of the methods for managing the structure and properties of materials, obtaining intermediate products, considered in the article, makes it possible to unify the individual characteristics of even low-quality raw materials and improve the quality of products. Il. 3, tab. 2, bibliography: 3 titles.
The boundaries of the area corresponding to kaolin samples from the Zhuravliniy Log deposit were determined in the MCO colorimetric system L * A * B * . It is shown that discriminant analysis makes it possible to interpret the processes of kaolin color formation after its processing at different temperatures, and to assess the contribution of variables - color coordinates - to the dominant processes in each heat treatment interval. A technique for identifying the latent (hidden) component of the coloring ability of iron compounds in kaolin is proposed. A multidimensional grading of kaolin samples by whiteness and yellowness by quality categories has been carried out. Tab. 6, ill. 3, bibliography: 8 titles.
The processes of activated sintering of oxide powders with different histories are considered. It is shown that there are two regions of particle sizes, more or less than 1 ?m, in which the mechanisms of compaction and hardening are significantly different. In this case, the general nature of deformation - diffusion-viscous flow - remains unchanged. Bibliography: 15 titles.
Sintering of heat-resistant beryllium oxide ceramics, formed by hot casting with the use of intense ultrasound, has been studied. It was found that changes associated with the homogenization of the material and a denser packing of powders at the stage of molding, as well as with the destruction and growth of defectiveness of particles, contribute to the intensification of sintering and make it possible to reduce the sintering temperature (50 - 150 ° C) and reduce shrinkage (10 - 20% ). Tab. 1, ill. 5, bibliography: 4 titles.
The sol-gel process of forsterite synthesis from magnesium acetate and tetraethoxysilane (TEOS) has been studied. The influence of the conditions of hydrolysis of TEOS on the morphology and phase composition of powders was studied. It was found that a stable sol, which turns into a gel, forms a solution of magnesium acetate and a hydrolyzate of TEOS in an acidic medium. In this case, the forsterite yield after heat treatment at 800 ° C is 97%. Carrying out hydrolysis in an alkaline medium and combining hydrolysis and precipitation of magnesium hydroxide provide a weakly aggregated powder with a composition close to monofractional, but increase the temperature of forsterite synthesis. Tab. 1, ill. 3, bibliography: 5 titles.
The results of the study of the influence of the electric field on the viscosity of thermoplastic ceramic slips VK95-1, VF52.42-1 and on the deformation of castings when the organic binder is removed are presented. It was found that when a constant electric field is applied, the viscosity of the thermoplastic slip decreases, with an increase in the field strength from 10 3 to 10 6 V / m, the viscosity decreases 3 times. The electric field contributes to the preservation of the shape of the ceramic casting (without deformation) during the removal of the organic binder from it and makes it possible to significantly (6 times) reduce the duration of this technological operation. Tab. 1, bibliography: 6 titles.
Possible ways of increasing the energy of oxide powders during sintering and ways of their activation are considered. This is achieved in the following cases. The first is an increase in temperature, i.e., the supply of thermal energy. The second is an increase in internal energy during mechanical grinding due to the energy of the surface and its defects. The third is an increase in the internal energy in chemical production methods under substantially nonequilibrium conditions due to the surface energy and surface and volume defects. Fourth, an increase in the internal energy upon the introduction of additives due to the energy of lattice deformation upon the introduction of foreign ions in general, since there are no two ions of the same size, and the energy of lattice defects upon the introduction of heterovalent ions. Bibliography: 22 titles.
