The properties of ceramic bonds used in the production of electrocorundum abrasive tools are given. Methods for studying the properties of ceramic bonds are considered, including methods that make it possible to study the process of sintering of the components of bonds and grains of electrocorundum and the formation of the structure of the bond and the contact zone of the bond and electrocorundum. Tab. 2, bibliography: 10 titles.
Experimental data on the effect of crystal size on high-temperature deformation in the field of mechanical forces of ceramic oxide materials are presented. It is shown that the main creep occurs by the mechanism of bulk diffusion of vacancies of impurity or nonstoichiometric origin (from the inner regions to the boundary). Il. 7, bibliography: 15 titles.
The thermostimulated luminescence (TSL) of BeO powders and ceramic samples obtained from the same batch of powder with a density of 2.10 - 2.93 g / cm 3 has been investigated. It was found that with an increase in the density of the BeO samples (respectively, with the average size of microcrystals), as well as with an increase in the vacuum in the cryostat chamber, a change in the position, number, and intensity of low- and high-temperature TSL peaks of adsorption and non-adsorption nature is observed. It is assumed that both impurity and adsorption centers of bulk and surface origin and intrinsic lattice defects are responsible for the formation of TSL centers in BeO powders and ceramics of various densities. Tab. 1, ill. 1, bibliography: 16 titles.
The kinetic parameters of mullite formation from oxides in the presence of mineralizers (B 2 O 3 and AlF 3 ) and with the addition of kaolinite (20%) have been studied experimentally. The degree of completeness of reactions, activation energy and rate constants for the reaction of mullite formation in different mixtures have been determined. It was shown that AlF 3 and kaolinite have the greatest accelerating effect. Tab. 1, ill. 2, bibliography: 8 titles.
The literature data on the compositions and properties of zinc-containing crystalline glazes for artistic ceramics are summarized. The modern ideas about the mechanism of crystallization and spherulite formation in the glaze coating are presented. The possibilities of controlling the crystallization process and decorative properties of glazes by varying the modes and parameters of their firing are shown. Examples of obtaining colored crystalline glazes are given. Tab. 2, bibliography: 19 titles.
On the basis of literature sources, the reasons and mechanism of the processes causing coloration of corundum ceramics are considered. Practical recommendations are given. Bibliography: 12 titles.
The results of the study of ceramic masses for the production of high-temperature porous ceramics are presented. The technology of producing a ceramic flame arrester on their basis is considered. Tab. 1, ill. 2, bibliography: 2 titles.
The possibility of using high-quality finely ground wollastonite in the composition of technical ceramics is considered. The technological modes of firing, the structure and physical and mechanical parameters of the obtained electrical insulators have been determined. Tab. 3, bibliography: 5 titles.
Experimental data on the effect of thermal, impurity, and nonstoichiometric vacancies on the diffusion creep of oxide ceramics at high temperatures and low mechanical loads are presented. It is shown that impurity and nonstoichiometric vacancies have the main effect on creep for materials of technical purity. The experimental data are fully described within the framework of the quasi-chemical approach, according to which the concentration of vacancies is determined by the law of mass action for the corresponding reactions of defect formation. Il. 8, bibliography: 16 titles.
The influence of refractory chamotte, additives of granite screenings, dolomite on alkali resistance and other properties of ceramic materials synthesized on the basis of refractory clay is considered. The regularities of changes in the properties of fired specimens depending on the RO / R 2 O ratio in the initial composition have been established. Tab. 1, ill. 1, bibliography: 1 titles.
