In the article, the creation of electrically conductive composite ceramics based on facing tiles with the addition of SiC with specified electrodynamics’ characteristics was considered. To obtain a press powder, the raw materials in a predetermined amount were weighed, 10, 20 and 30 % silicon carbide were added and subjected to wet grinding in a ball mill. The resulting slip was dried in a drying oven and passed through a № 05 sieve. The finished press powder for facing ceramics with SiC, moistened to 8 %, was weighed and poured into a mold for pressing, the pressure force was 18—20 MPa. The resulting green was dried in a drying oven. The semi-finished product was burned in a sillite furnace at a firing temperature of 1120—1140 °C with a holding at a maximum temperature of 5—10 minutes. The chemical composition of obtained press powder and the technological scheme for obtaining samples were presented. The obtained data shown that the best sample was facing ceramics with 30 % SiC, which had the following properties: water absorption — 5.9 %, open porosity — 12.5 %, apparent density — 2.13 g/cm2, resistivity — 0.43 ⋅10-6 Ohm ⋅m. The obtained X-ray diffraction pattern indicated the presence of silicon carbide in the sample after firing, which was confirmed by the data on the study of specific volumetric resistance of the studied ceramics and the obtained practical results.

Ceramic materials were synthesized in the RO(R=Ba, Sr)–Al2O3–SiO2 system using exothermic synthesis from solutions containing barium and strontium nitrates, silica and organic reducing agents (glycine and carbamide). It was shown that only the use of a mixture of glycine and carbamide as well as the addition of ammonium nitrate allows carrying out a complete exothermic synthesis with the formation of an X-ray amorphous product with a small fraction of the crystalline phase. It was established that monophase materials based on barium and strontium aluminosilicates (BaAl2Si2O8 and SrAl2Si2O8) are formed when the obtained X-ray amorphous product is heat-treated at the temperatures above 10000C. Ceramics from synthesized materials sintered at 15500C has a high refractoriness, open porosity of 0–1.0%, compressive strength of 115–120 MPa; dielectric constant of 3.25–6.0 (at the frequency of 1 MHz) and the loss tangent of (1.5–5.2)10–3. The results shows that the exothermic synthesis ensures the preparation of nano- and sub-microcrystalline powders in the system RO(R=Ba, Sr)–Al2O3–SiO2. Materials based on the obtained aluminosilicates can be used in the manufacture of protective structures for devices operating in the radio frequency band, in radar installations of aviation and rocket technology, in microwave elements, etc.

The article discusses the physical and mechanical regularities of ceramics formation based on the BaO—Al2O3—SiO2 system by slip casting into gypsum molds, and also investigates the rheological properties of a slip based on сelsian and the physicochemical properties of products made from it. The samples were made according to the following technology: the first stage is synthesis of celsian in a muffle furnace at a temperature of 1200 °C with a maximum temperature holding for 2 hours. The synthesis products were ground in a planetary mill to a residue on the № 0063 sieve of no more than 0.2 %. Then, slips with different moisture content without additives and with the addition of 0.10, 0.15 and 0.20 wt. % thinning additive Dolapix PC 67 were made. The second stage is to obtain samples by casting slip into gypsum molds. Firing of products took place in a muffle furnace at a temperature of 1350 °C with a two-hour holding. The optimal amount of thinning additive in the celsian slip was determined, which corresponds to 0.10 wt. %. It was found that, in the studied area of technological parameters, the material acquires the best properties at a sample firing temperature of 1350 °C and is characterized by the following indicators: water absorption — 10.20 %, apparent density — 2.15 g/cm3, open porosity — 21.04 %.

The article considers the slip casting technology of celsian-slavsonite ceramics with the ratio of raw materials to obtain crystalline phases of ВаAl2Si2O8: SrAl2Si2O8 – 25:75. The manufacture technology of product proceeded in two stages. The first stage of synthesis was performed in a muffle furnace at a rate of temperature of 15 deg / min at a maximum firing temperature of 1200 °C with a holding time of 2 hours. Then the synthesized ceramics were grinded for 10 minutes. The second stage was to obtain a slip with the addition of surfactants (DOLAPIX PC 67). The finished slip was poured into a plaster mold. Drying of the green sample was carried out in an oven at a temperature up to 110 °C for 3 hours. Firing of the dried sample was carried out in a muffle furnace at a rate of set temperature of 15 deg / min, at a maximum firing temperature of 1250 °C for 2 hours. The fired materials were subjected to machining. The obtained data indicate that, the best sample was fired at a temperature of 1250 ° C and had the following properties: dielectric constant — 9.4, water absorption — 5.9 %, open porosity — 14.4 %, apparent density — 2.42 g/cm3, flexural strength — 19 MPa.

The studies carried out concern the development of structural radiotransparent ceramic materials based on the four-component system BaO–SrO–Al2O3–SiO2. Due to the widespread use of radar equipment at modern aviation facilities, the development of radiotransparent fairings for them is a rather important and urgent task.The purpose of the fairings is to protect the antenna devices of radar stations from environmental influences during flight. Based on this, the fairings must meet a complex set of requirements for aerodynamic, thermal, radio engineering and mechanical properties. These requirements at supersonic flight speeds of modern objects increase significantly, since the improvement of the aerodynamic shape, the increase in the mechanical strength and thermal stability of the fairings contradicts the interests of radio engineering, leading to a significant deterioration in their radiotransparency and to distortions of antenna directional patterns. The consequence is a decrease in the range of radar stations and serious deterioration in their accuracy characteristics.The aim of the research was to obtain, on the basis of the BaO–SrO–Al2O3–SiO2 system, crystalline phases of slavsonit and celsian at low temperatures and times of synthesis, by introducing sintering intensifiers with fluxing and modifying action.The influence of a number of additives on the intensification of the low-temperature synthesis of slavsonit and celsian is investigated. The positive effect of the eutectic additive of the SnO2–Li2O system on the preparation of a densely sintered ceramic material based on solid solutions of slavsonit and monoclinic celsian is shown. It has been established that, according to its dielectric properties, the obtained ceramic material can be classified as structural radio-transparent materials.