The products of the synthesis of crystalline matrices, which are promising for the immobilization of actinides, have been studied by X-ray phase analysis. The experiments were carried out with compositions corresponding to the stoichiometry of the phases of zirconolite (CaZrTi 2 O 7 ) and pyrochlore (CaCeTi 2 O 7 , Gd 2 Ti 2 O 7 , Gd 2 Zr 2 O 7 ) structural types. The experiments were carried out in the temperature range 800 - 1600 ° C, sintering duration 5 - 50 h, in air and oxygen. The conditions for phase formation in matrices of various compositions have been determined. Practical recommendations are given. Tab. 5, bibliography: 11 titles.
Dispersed powders of tetragonal zirconia stabilized with Y 2 O 3 , Yb 2 O 3 and combined additive (Y 2 O 3 + CaO + MgO). Technological parameters of the processes of synthesis and preparation of the initial ZrO 2 powders intended for the manufacture of ceramics with increased strength parameters are proposed. Tab. 4, ill. 1, bibliography: 6 titles.
The effect of the nature of magnesium salts and a silica-containing component on the synthesis and properties of forsterite powder obtained by the sol-gel method has been studied. It was found that the use of magnesium acetate significantly reduces the temperature of the onset of forsterite formation, and it is preferable to use amorphous types of silica as the silica-containing component. Il. 3, bibliography: 7 titles.
New technical solutions in the technology of forming rod insulators with spiral ribs by drawing them directly from a vacuum press are considered. Positive results of comparative tests of tires with spiral and annular ribs have been obtained. Tab. 1, ill. 1, bibliography: 2 titles.
The influence of the clay component on the formation of the permeable structure of ceramic materials has been studied, and the possibility of using clays of the Tula region as a binder for permeable ceramics has been established. Tab. 2, ill. 3, bibliography: 3 titles.
Micropores in nanoporous ceramics prepared by pyrolysis of organosilicon polymers have been studied using the BET and mercury porosimetry methods. From the point of view of synergetics, an explanation is given for the low reproducibility of the obtained micropore structure. Bibliography: 7 titles.
With the help of model experiments carried out in the mode of linear heating of mixtures, which are promising refractory compositions: MCrO 4 + Mg + MgO and MCrO 4 + Al + Al 2 O 3 (M = Mg, Ca, Ba), the temperature regimes of the combustion reactions are determined. All processes of interaction of components were carried out using solid in-reaction oxidants - chromates of alkaline earth metals, which were also products of self-propagating high-temperature synthesis. The resulting refractories, in terms of their structural and physicochemical characteristics, are not inferior to products synthesized using conventional technology. Tab. 1, ill. 3, bibliography: 4 titles.
The issues of sintering ceramics based on corundum with a eutectic addition of the MnO - Al 2 O 3 - SiO 2 system from the standpoint of the evolution of its structure are considered. When sintering in the presence of a small amount of eutectic, the behavior of the system changes significantly before and after the appearance of the liquid phase. Before the formation of the liquid phase, the process is determined by the properties of the material in contact between the particles, after which the system becomes sensitive to the state of the contact surface between the solid phase and eutectic liquid. The latter is explained by the fact that the eutectic composition is practically saturated with respect to aluminum oxide. Tab. 1, ill. 2, bibliography: 12 titles.
The possibility of using high-calcium waste from chemical water treatment and a lithium-containing mineralizer in the production of ceramic tiles has been investigated. The processes occurring during their sintering are explained. Tab. 1, ill. 3, bibliography: 5 titles.
The results of obtaining highly dispersed cubic alumina by the method of chemical deposition from solutions of aluminum hydroxides with subsequent dehydration are presented. Il. 2.
