The mechanism of the formation process of aluminum nitride ceramics with a fibrous structure is investigated. The possibility of isomorphic substitution in the aluminum lattice by Si, Mg, Ca, Y atoms and other less deficient rare earth elements is shown. Tab. 1, ill. 3, bibliography: 5 titles.
Fractures of unbaked and heat-treated specimens in the temperature range 900 - 1200 ° C, obtained from a mixture of colored granules pressed at different pressures and unpainted powder, have been investigated. It is shown that the crack moves along the boundaries of the granules modulating the areas of local compaction, and after firing at temperatures of 1050 - 1100 ° C, the fracture becomes smoother. In this case, the system (workpiece) passes into an unstable state with bifurcation properties. An increase in the heating rate from 3.5 to 6.5 ° C / min leads to a shift in the transition from uneven to even cleavage, depending on the density of the original granules (the pressure of their pressing). The establishment of the main bifurcations in the technological process and their elimination opens the way to the creation of ceramics with a reproducible structure and properties. Tal. 4, ill. 1, bibliography: 10 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.
New technological parameters have been developed for molding pottery on a semi-automated production line. The laborious process of molding large-sized pottery has been mechanized, technical, economic and quality indicators have been improved, rejects have been reduced, and productivity has been increased. Tab. 2, ill. 1, bibliography: 2 titles.
The results of studies on the use of carborundum slab breakage for the manufacture of a finely dispersed heat-resistant capsule by slip casting are presented. The main physical and mechanical properties of the investigated masses based on plate breakage are not inferior to the mass prepared on the basis of silicon carbide. Experimental batches of capsules of various shapes had good performance properties. At the same time, the prime cost of the capsule is reduced by about 3 times. Tab. 3, ill. 2, bibliography: 6 titles.
The reasons for the change in the structure and properties of the porcelain mass subjected to aging are analyzed from the standpoint of using the patterns of development of microbial communities. It is shown that when a nutrient substrate is added to the porcelain mass, the vital activity of the natural microflora is stimulated, which is accompanied by a favorable change in the coagulation, condensation structure. This intensifies the sintering process and improves the degree of "maturation" of the porcelain. Tab. 8, ill. 2, bibliography: 31 titles.
Compositions of ceramic pigments for coloring glaze and flux coatings using the powder method and the co-deposition method have been developed. Comparative characteristics of the chromophore properties of the obtained pigments are presented. The expediency of using the co-deposition method for the synthesis of ceramic pigments is shown. Tab. 3, ill. 2, bibliography: 4 titles.
