VOL 93, No. 7 (2020)

When using almost all types of additive technologies, it is mandatory to use a binder with further heat treatment of the finished product. The binder compositions can be very diverse. Correct selection of the composition and properties of the ceramic powder - binder system at all stages of the process allows creating high-performance installations for producing parts of complex shapes. Presented are studies on the development of a binder composition for oxide aluminum-zirconium powders

The results of research on the production of fused materials based on kaolinite clay and high-alumina waste using a concentrated radiant flux are presented. The phase composition, microstructure, and elemental composition of the synthesized materials have been determined. It has been established that for the formation of an optimal microstructure in the form of acicular mullite with a multidirectional orientation, the most preferable is the mass content of the additive 10 - 20 & # 37; and the rate of cooling of the melt & # 8776; 10 ³ & # 176; C / s

Hardening composite materials based on calcium phosphates (hydroxyapatite, monocalcium phosphate monohydrate) and polymer binders (polyvinyl alcohol, polyvinyl pyrrolidone) have been obtained. It was found that with an increase in the content of acidic calcium phosphate in the composition, the amount of brushite and tricalcium phosphate increases. The introduction of polymer binders into the composition of hardening composite materials increases their mechanical strength and inhibits the structural phase transformations of calcium phosphates at 800 ° C. Compositions based on 5 & # 37; solutions of polymers and powders of hydroxyapatite or its mixture with a mass content of 10 - 40 & # 37; monocalcium phosphate monohydrate can be used as a consumable for 3D printing calcium phosphate biomaterials and ceramics

Various options for transport and technological schemes for unloading and storing substandard quartz sand used for the preparation of glass batch in compound shops are considered. The possibility of using quartz sand without additional processing in drying drums is noted. A method and a device for unloading bulk material from dump trucks with increased carrying capacity into receiving bins of small volume are presented.

The results of studies of performance indicators of samples of foam glass concrete building products are presented. For a more visual representation of the possibilities of using products in various conditions, the indicators are conditionally divided into strength and energy. Strength includes density and compressive strength, energy - thermal conductivity and moisture resistance. The qualitative results of the influence of the main parameters of the main filler of products - ground glass - on performance indicators have been investigated. Nomograms have been developed to determine the rational ratio of the output indicators of products in relation to various technical and operational requirements

The paper presents a study of the possibility of obtaining artificial porous aggregates for lightweight concrete based on household cullet and various types of ash and slag waste from thermal power plants: ash disposal, slag and ash and slag mixture from the ash dump. The influence of the type and amount of ash and slag waste in the composition of the charge, as well as the temperature and time of firing, on the final properties of the material has been investigated. The properties are determined and photographs of the macro- and microstructure of the obtained experimental samples of artificial porous filler are presented.

The analysis of the main reasons for the formation of efflorescence in brickwork in the Aral Sea regions is presented. It has been established that as a result of alternating moistening and drying of the building material, during which the crystallization of salts in its pores occurs, the formation of high-water crystalline hydrates with an increase in volumes exceeding the pore volume of the material leads to the appearance of pressure that destroys the building material. External signs of salt corrosion are peeling and chipping of ceramic bricks. The features of salting out in ceramic bricks in the Aral Sea conditions are indicated.

The object of the research is ceramic material taken from the fortress wall of the city of Girona. The chemical composition of the test material showed an increased carbon content (13.1 & # 37;), which indicates the introduction of fuel into the raw material. The increased content of fuel in the raw material contributes to the formation of porosity and uniform sintering inside the ceramic specimen. Integral and differential porograms of the samples under study, obtained by the method of mercury porosimetry, showed that the total volume of micropores ranging in size from 10-4 to 10-8 m is 0.155 cm ³ / g. The differential distribution of micropores, depending on their size, is as follows: 10-4? 10-5 - 27 & # 37; (backup - non-hazardous); 10 ? 5 ? 10 ? 6 m - 19 & # 37; (dangerous); 10? 6? 10? 7 m? 29 & # 37 ;; 10? 7? 10? 8 m? 25 & # 37; (non-hazardous)

Microstructural studies of ancient Issyk-Kul ceramics were carried out using a scanning electron microscope, which allows not only to see the mutual arrangement of mineral particles, pores and microcracks, but also to carry out a quantitative analysis of the main microstructural indicators. Ceramic samples from the valley of Lake Issyk-Kul (Kyrgyz Republic), where the ruins of many ancient settlements are located