VOL 94, No. 6 (2021)

Organo-inorganic hybrid materials based on inorganic oxofluoride lead-borosilicate glass matrices and a metal complex compound of tris- (8-oxycholate) it-terbium (III) were obtained by the melt method. The spectral-luminescent properties of tris- (8-oxycholate) ytterbium and hybrid materials in the visible and IR regions have been studied at various excitations (377 and 785 nm). It is shown that the intensity of IR luminescence in the initial metal-complex phosphor exceeds the luminescence in the visible region, and in the obtained hybrid materials, on the contrary: the intensity of visible luminescence is significantly higher than the IR luminescence.

The structure of the surface layer of ceramic composite materials (CMC) of the compositions HfB ₂ & # 8211; SiC and SiC & # 8211; TiC after exposure to a flow of dissociated air has been investigated. X-ray structural analysis of the surface, analysis of the microstructure of the surface layer by scanning and transmission electron microscopy methods were carried out. The features of the formation of glassy layers on the surface of CMC with refractory oxides distributed in them are shown. The internal volume of materials contains unoxidized starting components

The characteristics of composite materials of the Al ₂ O ₃ & # 8211; carbon nanotubes & # 8211; eutectic additives. The influence of the content of the reinforcing component, as well as the mode of high-temperature heat treatment in vacuum on the strength properties of the material is considered. Samples were obtained with a mass content of carbon tubes of 0.4 & # 37; having the following characteristics: average tensile strength at three-point bending 380 MPa, open porosity 0.9 & # 37;, average density 3.71 g / cm ³

The preparation and mechanical properties of composites 20 & # 37; molar fraction of Al ₂ O ₃ and 80 & # 37; [3Yb & # 8211; TZP] modified with strontium oxide. It is shown that in the process of heat treatment of the initial nanopowders, the strontium hexaaluminate phase is formed in situ. A correlation has been established between an increase in the concentration of the modifier and an increase in the volume fraction of the strontium hexaaluminate phase. It was revealed that the content of the modifier is higher than 3 & # 37; leads to an increase in the porosity of the composites. Determined that composites modified 1 & # 8211; 2 & # 37; molar fraction of SrO, have a flexural strength of 850 MPa, fracture toughness K _1c up to 11.3 MPa

Comprehensive studies of anorthite-containing building ceramics, obtained on the basis of clay and sludge waste from metallurgical production, have been carried out. Component compositions were selected to obtain ceramic products with a predominant content of the anorthite phase. The physicomechanical characteristics, phase formation and morphology of the prepared ceramic samples have been investigated. It has been established that the structure formation of the anorthite phase in the composition of ceramic samples is formed at a mass content of sludge waste from metallurgical production from 10 to 50 & # 37 ;. An increase in the strength characteristics of ceramic samples occurs due to the content of prismatic and needle-shaped crystals of the anorthite phase, evenly distributed throughout the entire ceramic mass of the sample.

The properties of the earthenware surface are determined & # 8211; acidity and aluminosilicate modulus and explained their change depending on the chemical composition with a change in the content of mullite Al ₂ Si ₂ O ₅, quartz and cristobalite (crystalline modification of quartz SiO ₂). In accordance with the structure of the surface, the presence of a negative surface charge was determined. It was found that silanol groups on the surface of Si & # 8211; OH earthenware, which have weakly acidic properties, provide physicochemical interaction with polymer film-forming materials with basic properties. The sorption of urea-formaldehyde oligomers of various compositions on faience and subsequent film formation in the presence of polyvinyl alcohol is considered.

Within the framework of the theory of developed evaporation of matter under the action of laser radiation, the problem of assessing the strength of ceramic parts of a cylindrical shape during laser punching of holes in them is considered. Analytical relations are obtained for calculating the power density of laser radiation, which leads to the destruction of the lateral surface of parts by the pressure of gaseous products as a function of the ratio of the hole radius to the radius of the part, the ratio of the radius of the part to the radius of the hole in it, and the thickness of the lateral surface of the part as a function of the power density of the acting laser radiation. Using the example of technical ceramics based on magnesium oxide P-25, the applicability of the results obtained for assessing the strength of cylindrical parts is shown. When the ratio of the hole radius to the part radius is less than 0.3, the part can be considered as an infinite body. In this case, the error in the calculations will not exceed 10 & # 37;

The results of studies of the chemical and mineralogical characteristics of alumina-containing wastes of the gas processing industry and the possibilities of their use for the synthesis of aluminum-magnesium spinel are presented. It was found that the optimal condition for the synthesis of spinel MgAl ₂ O ₄ by the sol-gel method using alumina-containing waste is a temperature of 1000 ° C and a holding time of 120 min.