Materials Science Forum Vol. 1037

Abstract: Polypropylene expansion tanks have been subjected to accelerated weathering testing according to the developed procedure of accelerated weathering testing. The objective of the study was to determine an arbitrary lifetime of tanks under operating conditions at higher temperatures, humidity, and UV radiation (climate regions of India and Venezuela). As a result of the studies of the polypropylene expansion tanks the following has been established: the failure of the both tank types (A and B) occurred in the area of the weld in the upper and lower part after four arbitrary years of accelerated weathering testing; the stress-strain behaviour in the outer tank walls is influenced by the interior structure of the partitions. The tanks with a larger opening in the partitions feature significant deformations when the inner pressure increases as a result of a higher temperature; the “sensitive indicators” of ageing and failure of the tank material have been found: elongation at break, flexural modulus, and impact strength.

Abstract: This paper presents the development of methods for improving the thermal conductivity of fiber reinforcing materials based on the fabric structures. The thermal analysis of fabric structure in thermal load calculation is performed by Fourier’s Law of Thermal Conduction and Steady-State Thermal calculation in Siemens NX. This study leads to the development of thermal conductivity in manufacturing technology of fiber reinforcing materials. Keywords: Thermal conductivity, fabric structure, polymer composite materials

Abstract: The post-sintering properties of walling high-calcium ceramics based on clay-containing raw materials in low-temperature roasting depend on the chemical-mineralogical composition of clay with different contents of iron, calcium-containing and alkaline oxides that contribute to the formation of new crystalline phases, which provide for the production of low-density ceramic material with high-strength properties.

Abstract: The paper presents the results of tests of carbon plastic samples consisting of carbon fabric Grafill TR30S-S (Italy) and epoxy resin binder EPR 320 modified by WC tungsten carbide nanopowders in the form of agglomerates. The positive effect of additives on the tensile strength and on the modulus of elasticity at transverse bending of the concentration of additives 1-3% is shown.

Abstract: The essence of the hydraulic fracturing method for enhancing oil recovery is described. The definition of proppants is given and their average chemical composition is determined. In the process of an analytical review, the article presents proppants that are widely used in the oil industry. For each type of proppant, the main technical characteristics (bulk density and compressive strength) required when using the hydraulic fracturing method have been determined. In the course of the analysis, it was found that all proppant technologies are expensive and it is necessary to select high-quality cheap and affordable materials to reduce the cost of their production. Drilling cuttings from the Morozovskoye field were chosen as one of these materials. Physical and chemical studies of drill cuttings were carried out, on the basis of which a conclusion was made about the possibility of its use in the synthesis of high-quality aluminosilicate proppants.

Abstract: Basalt plastic, thanks to its complex of valuable operational properties, has a potential variety of applications. the article describes the technology of production of basalt plastics with various types of hybrid matrices, one of the components of which is cured in the molding process, and the second-like a binder in natural materials, retains its viscoelastic state. The viscoelastic component makes it possible to increase the deformation properties in the zones of their location, preventing cracking under increased loads. As a result of the conducted mechanical tensile tests, the average values of absolute breaking forces, tensile strength and elongation during fracture of basalt plastic samples with different types of hybrid matrices were obtained. The addition of viscoelastic components (such as technical wax, anaerobic, and organosilicon polymer materials) to the basalt plastic matrix allows to increase the elongation at fracture by 2...5%. Anaerobic polymer material in the basalt plastic matrix allows to increase the tensile strength of the composite material, as well as significantly reduce the dispersion of the measured values. This provides an effective prediction of the operational properties of the structural material in the design of products. On the basis of microanalysis of the structure of basalt plastics with different types of hybrid matrices, an explanation of the causes of changes in the mechanical properties of the resulting composite materials is given.

Abstract: In this article we investigated properties of elementary carbon fibers after their activation and subsequent deposition of thin layers of metal coatings on their surface. For deposition we used copper, titanium and stainless steel. We investigated influence of various technologies of preliminary processing of the fiber surface on the value of the adhesion strength of the metal coating to the carbon tape and on the mechanical properties of elementary fibers. We established that the strength of carbon plastics at interlayer shear increases by 10-30% when using carbon tapes and fabrics with a metal coating.

Abstract: Materials based on partially stabilized zirconia (ceramics and crystals) are distinguished by high values of mechanical strength, crack resistance, hardness, corrosion resistance, low coefficient of friction when operating in tandem with most metals, which makes them promising materials for a wide tribotechnical application in highly loaded friction units. An example of such a unit is the die mechanism, which is an integral part of the drawing die tool in the cable industry. These hard precision tools (drawing dies or wire dies) actually determine the ultimate success in the wire drawing process.

Abstract: The possibility and efficiency of the use of high-density polyethylene as a binding substance in grinding wheels for cutting-off, as well as for finish cylindrical grinding, is researched. It is determined that: - breaking mechanical strength of such circles ensures their safe operation at maximum operating speeds of 30–35 m/sec; - the use of high-density polyethylene as a binding substance in cutting wheels is not advisable, due to intensive wear and low cutting power of these tools; - wheels for finish cylindrical grinding on the basis of high-density polyethylene and hollow spherocorundum as abrasive grains in a number of key indicators (cutting power, roughness of machined surfaces) are highly competitive with grinding wheels on a bakelite bond or are comparable to them, and significantly exceed the latter in terms of wear resistance.

Abstract: The conditions for the synthesis of Al-Cr-W alloys during the aluminothermic reduction of a mineral tungsten concentrate - scheelite were considered. The alloys were identified as an aluminum matrix by the methods of elemental and X-ray phase analyzes. It is shown that the alloy synthesized from scheelite concentrate contains small amounts of iron and oxygen impurities (1.2 wt. %). It has been established that the alloys have a composite structure: inclusions of continuously solid solutions based on chromium and tungsten, as well as chromium aluminides Al₃(Cr, W, Fe)2, which have increased microhardness values (12.9 GPa) are distributed in the aluminum matrix.