In the development of standard magnetic methods for polyoperative control of the content of magneto-active (ferrous) particles in samples of bulk media (in particular, glass and ceramic industries), an analyzer of operational control was developed on the basis of an improved version of this method with higher accuracy. Its work was tested on natural raw materials, in particular, feldspar and quarz sand – with the results of control of experimental mass-operational (functionally extrapolated) characteristics according to the data of particle extraction from the sample of controlled raw materials.
Doped zinc-phosphate (ZP) glasses of compositions ZP:Ag:Au and ZP:Ag:Rb were synthesized by the melt quenching method both without and with the use of additional heat post-treatment at T = 500 °C. In the obtained glasses, bimetallic nanoparticles (NPs) of compositions AgAu and AgRb were formed respectively, along with the silver NPs. The ratio of the Ag and Au components in the AgAu NPs was estimated. The use of post T-treatment in the synthesis of glasses of composition ZP:Ag:Au led to an increase in the average size of NPs from ~4.5 nm to ~12.1 nm. Besides, both the minimum size of the NPs and the fraction of larger NPs with sizes ?15 nm increased. T-treatment for the sample of composition ZP:Ag:Rb did not lead to a noticeable change in the average size of NPs, which remained within 4.5…4.7 nm. However, the fraction of larger NPs (up to 20 nm) increased in the size distribution. A 3.5-fold increase in the intensity of Nd3+ ions emission at the wavelength of 1060 nm, excited by radiation with ?excit = 525 nm in the sample ZP:Ag:Au:Nd, was obtained compared to the glass sample without plasmonic metals. The decisive role of subnanometer nanoclusters (NCs) and NPs of the compositions Ag and AgAu in the observed increase of Nd emission intensity upon excitation with a wavelength of ?excit = 525 nm was established. The use of the post T-treatment for the glass of composition ZP:Ag:Au:Nd led to the transformation of Ag NCs into NPs, which resulted in a decrease in the enhancement of the Nd3+ ions emission intensity compared to the sample without heat treatment. When Nd3+ ions were excited by radiation with ?excit = 785 nm, far from the excitation of LSPR in Ag and AgAu NPs, the T-treatment performed during the synthesis of glass with composition ZP:Ag:Au:Nd did not noticeably affect the intensity of the Nd3+ emission line, which indicated the absence of clustering of neodymium ions at the elevated temperatures and duration of post-treatment used.
In this work, the effect of mechanochemical activation time of mixtures of initial components on the sintering of magnesium titanate ceramics is studied. The apparent activation energy of sintering samples is calculated using a non-isothermal method. The effect of increasing the firing temperature from 1300 to 1400 ?C on the density and porosity, as well as its microstructure of ceramics was studied. Ceramics obtained at 1400 ?C shows the best properties: ?av = 3.06 g/cm3 and P0 = 8.4 %.
Laboratory samples of reaction-sintered silicon carbide ceramics with permanent adhesive joints were obtained based on isopropyl alcohol and phenol-formaldehyde resin solutions with different contents of carbide and carbon particles. The joints have the following key structural physical and mechanical characteristics depending on the ratio of the phase components formed in the volumetric joining zone: thickness of the silicon layer in the seam is 20…130 ?m, flexural strength is 40…250 MPa, longitudinal sound velocity is 10 750…11 300 m/s, density is 3.07…3.08 g/cm3. It was experimentally established that varying the content of silicon carbide particles in the adhesive suspension from 20 to 80 % by weight makes it possible to achieve 30…75 % of the strength of the base material of the reaction-sintered silicon carbide ceramics.
A composite material obtained by ceramic technology from electrofused corundum and finely dispersed glass is used to simulate the formation of the pore space of a porous ceramic material. According to the rate of free water saturation, the ratio of volumes of through and dead-end pores in samples obtained from powders of different granulometric composition at different sintering temperatures was estimated. For samples of composites with an open porosity of 36…50 %, the size of the pore channels was estimated using capillary porometry. The correlation between the average pore size and the granulometric composition of the powders used in the production of composite materials is demonstrated.
Radiation-resistant glass of the K-208 brand has been used for a long time as a protective coating for solar panels and thermoregulating coatings (TPMS) of spacecraft in the form of thin plates with a thickness of 100...200 microns. The methods of cleaning the surface of protective coatings in the form of glass tape and nozzles for the manufacture of glass elements of TRP are compared and the advantages of the method of laser cleaning of their surface are formulated.
An overview of the applications of zirconium dioxide, partially stabilized with yttrium oxide, in various high-tech fields is presented. Particular attention is paid to its use in supercapacitors, where this material significantly increases the stability of devices during long-term cyclic tests, which is critically important for their practical application. In the field of solid oxide fuel cells, zirconium dioxide, partially stabilized with yttrium oxide, demonstrates exceptional characteristics, acting as an electrolyte, anode and membranes. When operating in the temperature range of 800...1000 °C, the material provides high ionic oxygen conductivity, which directly affects the efficiency of the entire fuel cell. In microelectronics, zirconium dioxide stabilized with yttrium oxide is used in the manufacture of thin-film transistors, where its outstanding dielectric properties and thermal stability become determining factors. This allows you to create reliable and high-performance electronic components. In the aviation industry and the production of gas turbine engines, zirconium dioxide, partially stabilized with yttrium oxide, is used as a heat-protective coating for hot path parts. The material demonstrates excellent resistance to extreme temperature loads, making it an ideal solution for protecting critical components. Various methods of applying such coatings, including plasma spraying and chemical deposition from the gas phase, are considered, as well as a detailed analysis of their characteristics, including layering, porosity, crystal structure of coatings and their thermal stability.
The article briefly describes the history of cooperation between the Glass and Ceramics magazine and the Department of Chemical Technology of Ceramics and Refractories at the Mendeleev University of Chemical Technology, which has been ongoing for over 90 years.
The article is a brief excursion into the history of long-term interaction of the “Glass and Ceramics” journal and the department of chemical technology of glass and glass-ceramics at the Mendeleev university of chemical technology.
The formation of micro-regions with altered refractive index in the volume of float and quartz glasses under the action of single femtosecond pulses has been studied. The phase distributions of the light passing through the micro-regions during observation along the recording direction and perpendicular to it are plotted. The influence of pulse energy on the magnitude of the phase change has been studied. It is established that the minimum energy of formation of micro-regions in the volume of float glass is lower than in quartz glass. The results obtained are of interest for creating analog sound carriers by modifying the glass structure with femtosecond laser pulses.
