The effect of the firing temperature and heating rate on the content of elemental iron in specimens based on montmorillonite clays of the Orenburg region has been investigated. It was established by X-ray fluorescence analysis that the iron content in the samples based on kaolinite-containing clay and a mixture of clays does not change in the temperature range under study. The possibility of using the content of elemental iron as marks for controlling the sintering stages of aluminosilicate ceramics is shown.
An overview of the prospects for the use of glazing products of aviation technology based on silicate, organic, polycarbonate glasses from the standpoint of strength, main sources of loading and the most vulnerable points is presented, proposals for improving their strength reliability are described.
The chemical activity to cement alkalis (ASR-resistance) of granular aggregates (Penosital & # 174 ;, classic foam glass, fly ash microspheres) in a water extract from concrete has been investigated. The main conditions for achieving ASR-resistance of aggregates, which correspond to the foam and microspheres of fly ash, have been determined.
The coatings on glass witness samples were investigated, which made it possible to record the technological modes of their application, as well as the parameters of the installation: operating current, voltage, limiting and operating vacuum, the required number of coating layers. Measurement of the resistance of metallized coatings on nonwoven materials obtained under certain conditions showed a value from 32 to 11 Ohm / cm 2 , which was set by the conditions of the experiment
Analyzed are the mass-operational characteristics of the magnetic control of ferro-impurities of raw materials (quartz sand, feldspar, gypsum), obeying the exponential both completely and partially (tail section), when the use of an experimental-calculation model for controlling ferro-impurities is possible taking into account the corresponding amendments. On the example of using different field sources, it is shown that the results of magnetic control with a limited number of operations differ significantly among themselves, and with an unlimited one (experimental calculation method), despite the change in the & # 171; form & # 187; mass-operating characteristics remain practically the same
A porous composite material based on zirconium oxide fibers has been obtained, which has a high resistance to the action of a concentrated alkaline solution and satisfactory mechanical strength. Samples were made with different pore sizes in layers that perform different functions. The study of the obtained samples showed that zirconium oxide fibers with high thermal stability and chemical resistance, especially to the action of alkalis, have good prospects for the manufacture of separators for alkaline batteries, especially in cases where it is necessary to combine high energy characteristics with increased reliability and service life.
The effect of two deflocculants that effectively reduce the viscosity of the cement paste has been investigated. sodium tripolyphosphate (PF) and Castament FS 20 (C1) based on polycarboxylate ether and their mixture on the structure of a cement stone with microsilica after holding at a temperature of 65 ° C, drying and firing. In the course of aging, the mineral strutlingite is additionally formed in the samples with C1. It was found that C1 promotes the active formation of the mineral anorthite, while PF? crystallization of gehlenite during firing. When a mixture of PF and C1 is used, crystallization of anorthite prevails in the sample. The results of the density and strength of concrete specimens with PF are higher than those of specimens with C1, however, the shrinkage phenomena in them are greatest. The equal ratio of PF and C1 in the mixture reduces shrinkage, allowing you to obtain the highest strength and density of concrete after firing at a temperature of 1200 ° C
The chemical resistance, changes in the composition and structure of materials based on fused minerals and sodium water glass have been studied when interacting with corrosive liquids. It was determined by the methods of IR spectroscopy and chemical analysis that upon exposure to acids, the degree of polymerization of silicate compositions increases in proportion to a decrease in the content of modifier cations. The action of an alkaline solution leads to a shift of the stretching vibration bands of Si - O - Si bonds to the low-frequency region due to a decrease in the content of SiO 2 . All tested materials are resistant to water and 3 & # 37; -th CH 3 COOH. In solutions of 20 & # 37; -th H 2 SO 4 and 35 & # 37; -th NaOH materials based on fused pyroxenes have maximum stability
The features of the macrostructure of rigid heat-insulating materials based on fibers of mullite-corundum composition are considered, the change in the physical and mechanical properties of materials over the volume of the sample is shown. The reasons for the appearance of defects are analyzed and the ways to increase the isotropy of the properties of the fibrous material are outlined.
In the framework of the one-dimensional problem of the evaporation of an absorbing layer of matter at & # 171; instantaneous & # 187; For the release of laser pulse energy, analytical relations are obtained for calculating the energy density required to pierce through holes in non-metallic plates, for three variants of laser radiation exposure, and also for calculating the evaporated mass of a substance per unit of input energy. A comparative analysis of the options for the effect of laser radiation on a plate is carried out, showing the possibility of reducing energy costs when piercing through holes in glassy and ceramic plates.
