The issues of creating three-dimensional structures of a given architecture based on pyrophosphate ceramics by the method of a removable additive are considered. The problems of filling a polymer negative, printed on a 3D printer, with a powder precursor, as well as maintaining the structure of the material during polymer removal, have been resolved. The processes of sintering of ceramic materials, as well as the mechanical characteristics of the obtained materials have been studied.
Dense materials based on silicon carbide were obtained by liquid-phase sintering. The oxides MgO, Y 2 O 3 and Al 2 O 3 , corresponding to the composition of yttrium-aluminum garnet, were used as a sintering additive. and a triple eutectic point on the line of spinel garnet binary cuts. The oxides were deposited on the surface of the powder by the SiC method of coprecipitation from a salt solution. The maximum density (& # 961; rel = 99.5 & # 37;) is achieved on SiC materials including 20 & # 37; (mass content) of sintering additives of a three-component oxide mixture at a temperature of 1800 & # 176; С
The factors affecting the thermal conductivity of ceramic composite materials based on SiC with additives B 4 C, AlN, Si 3 N 4 , Y 2 O 3 , Al 2 O 3 , HfB 2 , obtained by spark plasma sintering technology with a relative density of 99 & # 37 ;. Thermophysical properties were determined in the temperature range from 20 to 1300 ° C: heat capacity, thermal diffusivity and thermal conductivity of composites. Thermal diffusivity and heat capacity were measured by the laser flash method. The heat capacity measurements are supplemented by the results obtained by DSC and adiabatic calorimeter methods. Thermal conductivity is calculated from the data of thermal diffusivity, heat capacity and density.
An overview of the current state of theoretical studies of close-packed systems of hard spheres is presented. A description of the main models of regular and random dense packings of rigid spheres is given. Examples of the application of modeling of dense packing of rigid spheres for solving applied problems in the field of creating promising materials from ceramics, including refractories, are given.
A review of dissertations by Russian scientists on ceramics made of aluminum oxide, methods of its preparation for the period since 2000 is presented. Thin structural ceramics are mainly considered. The emphasis is on technological aspects. The second part of the review includes the synthesis of aluminum oxide nanopowders and their use for sintering, the sol-gel method for obtaining Al 2 O 3 , other methods for the synthesis of fine and fibrous Al 2 < / sub> O 3 for corundum ceramics
The chemical and mineralogical compositions and physicochemical characteristics of the Yazyavan dune sands, as well as their suitability for use together with other raw materials of Uzbekistan to obtain optimal compositions of ceramic facing tiles, have been studied. It has been established that the mass content of dune sand in the composition of the ceramic mass of facing tiles in a triple and quadruple composition should be no more than 45 and 25 & # 37; respectively. The optimal technological parameters for the production of ceramic tiles using dune sands that meet the requirements of GOST 6141-91 have been determined
In the Li 2 O-ZnO-TiO 2 system, a material with a sintering temperature of 950 ° C has been developed for the technology of low-temperature co-firing of ceramics, which can be used for the production of electronic components ... The influence of the content of the sintering additive of the eutectic composition in the Li 2 O-ZnO-B 2 O 3 system, as well as the method of its synthesis on the compaction and dielectric properties of the resulting material. The developed ceramic is characterized by a dielectric constant ? = 17.7 and a dielectric figure of merit equal to 407 MHz
A review of domestic dissertations on ceramics from aluminum oxide, methods of its preparation for the period since 2000 is presented. Thin structural ceramics are mainly considered. The emphasis is on technological aspects. The first part of the review includes sintering Al 2 O 3 with additions of heteroelement oxides, reaction sintering with the addition of aluminum, and obtaining cermets of the Al 2 O type 3 -Al, obtaining reinforced composites with an alumina matrix
Experimental samples of ceramic composite materials in the SiC-ZrB 2 system with additions of graphite and aluminum nitride were obtained by the method of spark plasma sintering. The physical and mechanical properties of composites (density, bending strength, hardness, crack resistance) were investigated depending on the temperature parameters of their preparation. The microstructure of the materials has been studied and micro-X-ray spectral analysis has been carried out, the oxidation resistance of the obtained samples has been determined at a temperature of 1500 ° C.
The results of theoretical and experimental studies of methods for obtaining powder fillings with a relative density of more than 0.50 for subsequent sintering of samples of high-density ceramics based on aluminum oxide are presented. To achieve the specified compacting density, we used the method of selecting the fractional composition of the spherical corundum powder, based on the known theoretical models of dense regular and random packings of spheres of different sizes. The prospects of using the described methods in the technology of manufacturing ceramic products are assessed.
