Materials Science Forum Vol. 1022

Abstract: The paper considers the current state of the mineral raw material base and the construction material market of the Rostov Region. The effect of various factors on the strain-stress behavior of local limestones has been investigated. The scientific and technical literary sources devoted to the processes of rock failure under various loads have been analyzed. The experimental studies have shown that the tested samples of limestone with a high content of cuboidal grains have characteristics comparable to those of the crushed granite stone. It has been concluded that the use of the Rostov Region limestones in the construction industry is competitive and feasible, provided the proper implementation of the engineering measures proposed in their production.

Abstract: Within the scope of this work, the methods of the experimental research of SHS processes during HFC-heating, particularly of hardening coatings applied on samples by HFC-heating have been developed. A study of the composition and properties of the products formed during the SHS process in the basic mixture on the surface of S355 steel parts during HFC-heating has been made, and it has been shown that aluminum oxide, aluminum nitride (by-product), and amorphous boron are formed under these conditions, and composite porous inhomogeneous coatings up to 250 microns thick, based on aluminum oxide, SHS products in the basic mixture and traces of high-speed HFC-boriding products are formed on the workpiece surface.

Abstract: Metal structures, pipelines and dies are used for a long time wear out and deteriorate. At the end of the service life it is necessary to repair or replace the metal component. The article discusses the method of applying nickel super-alloy Inconel 625 by direct laser deposition on high-alloy austenitic Mn-Cr steel. The article discusses the method of applying nickel super-alloy Inconel 625 by direct laser deposition on high-alloy austenitic Mn-Cr steel. Inconel 625 alloy is used as a buffer layer or repair material. But there is a high probability of cracks in the cladding material and the substrate material when the DLD method is used. One of the frequent causes of these cracks is high tensile stresses and oxides. To eliminate defects, the substrate was heated with resistive heaters to 400 °C. The result was a defect-free adhesion of the cladding material and the substrate. The hardness of the substrate before and after heating has not changed (312 HV 0,5/10). After heating the hardness of the substrate in the heat-affected zone decreased by 14% and was equal to 267 HV 0,5/10. The hardness of the cladding decreased by 12% and was equal to 230 HV 0,5/10.

Abstract: In this work, data on the development of such an important section of Electrical Engineering as “Electrical conductors and methods for their manufacture” are gathered together. The information collected will allow you to compare different materials suitable for the manufacture of electrically conductive structures. The paper also has a history of the development of this section, as well as a patent study of relevant and unusual methods for the manufacture of electrical conductors.

Abstract: The paper presents the surface structure formation of AISI 304 stainless steel using the MiniMarker2-20A4 laser system. Austenitic steel was in the form of a cold-rolled sheet and a tape of increased strength for parts and structures. The article reviews the corrosion-resistant steel surface condition after analyzing the influence of power, frequency and speed of the laser and evaluates the impact on the corrosion resistance of the treated surface. The contrast assessment shows the treated structure effect on the alloy surface reflectivity. The calculations of the most optimal marking are made for obtaining the greatest contrast. The maximum contrast obtained as a result of parameter optimization was 0.83 and was improved by 10%. The article also touches on the influence and susceptibility to corrosion of stainless steel samples with laser marking by QR codes. This point displays structural change of the processed area and presentations steel surface structure AISI 304 after corrosion tests.

Abstract: The article discusses the problems of ensuring high-quality formation and normative properties of butt joints of the 1560M and 1980T1 (AMg6 and B48) aluminum alloys as applied to engineering. A method is proposed for joining materials by means of EBW using an electron beam sweep. Homogeneous and dissimilar joints have been investigated, heat treatment of joint from the 1980T1 alloy and a dissimilar joint from the 1560M + 1980T1 alloys is recommended. The paper also presents the results of mechanical properties testing, the corrosion resistance and the delayed fracture tests. A welding technology that makes it possible to obtain high-quality butt-welded joints from aluminum alloys in thicknesses up to 40 mm has been developed and implemented.

Abstract: The use of borate fluxes is an important component of the part hardening process by HFC-heating. The article discusses the possibility of using various coatings to saturate the surface of steel parts, as well as the features of using various boriding agents. Microstructures of the obtained boride coatings at various fractions of the boriding agent have been considered, and the areas of carbide inclusions and average thickness of the resulting coatings have been analyzed. The expediency of P-0.66 fused flux using and changes in the resulting coatings due to the changes in the mass fraction of this flux in various boriding mixtures have been investigated. Based on the obtained data on the microstructures of boride coatings, conclusions were made concerning the most appropriate compositions of boriding mixtures and the mass fraction of fused flux in their composition.

Abstract: The article gives the description of experimental studies on the assessment of changes in the state of gear teeth of a mechanical transmission during tests on a stand with a closed power flow. Data on the gears made of cast iron materials are presented. The strength characteristics of gear wheel materials and their chemical composition are given. Operational life testing of gear sets with various geometries of gearing and made of gray cast was carried out. According to the conducted studies, it is found that by the optimization of the gearing parameters it is possible to increase the gear life by one and a half to two times without switching to more wear-resistant and durable materials. It is experimentally proved that the influence of geometrical parameters of gearing with combined displacement on the durability of gears is comparable with the replacement of material. When replacing the material of gears made of gray cast iron with alloy grades of cast iron, preference should be given to high-alloy wear-resistant cast iron with a surface hardness above average, and the effect of their use can be comparable to the effect of optimizing the gearing parameters.

Abstract: The use of ultrasonic smoothing methods for metal sheet materials opens up new opportunities for improving their performance properties. The paper considers the possibility of increasing the axial stiffness of aluminium thin-walled machine parts by reducing the size of their grains and creating conditions for obtaining nanostructured formations. It has been found that the yield strength of the 8011 grade foil treated with two-way ultrasonic smoothing, depending on the depth of the hardened layer, microstructure and grain size, initially decreases to the middle section, and then increases to its largest value. According to a similar relationship, the relative elongation, i.e. the plasticity of a thin-walled part, changes which also confirms the possibility of formation of nanostructures in the studied layers. Experimental studies have established that the two-way ultrasonic treatment of multilayered plates made of aluminium 8011 grade foil with a thickness of 0.42 mm allows to provide high plasticity and to increase its axial rigidity up to 20.6%, thereby improving the manufacturability of complex machine parts from thin-walled plates by the methods of cold treatment.

Abstract: In all industries, composite materials with a multilayer structure are widely used. Each layer of the composite material is a directional fiber impregnated with a binder polymer. Layered composite materials, possessing unique properties and high manufacturability, have a significant drawback - the presence of interlayer defects in material, which reduces the scope of their application. One of the perspective directions for reducing the process of interlayer fracture in composite materials is the use of bulk textile material, which is the reinforcement of the entire multilayer material. This article presents an overview of some researches that provide basic information about the creation of perspective composite material made of volume fabric and materials based on them. We provided open information about manufacturers of 3D fabric materials. We carried out experimental tests with composite materials, which showed that material with transverse threads is 30-35% stronger during end impact than a composite material without reinforcement.