bluuebunny/crossref_metadata_2025 huggingface dataset:
Problems of Autoclaved Aerated Concrete Treatment
Authors: Vishnevsky Andrey , Kapustin Fedor L.
Published: October 2018

The problems of autoclave c of cellular concrete are considered. It was shown that the key problem of autoclaving is the appearance of areas of concrete with different dark colors and a reduced strength. The main reason for their occurrence is the presence of air in the porous space of cellular concrete, which prevents heat transfer. Cold air does not allow the concrete to warm up to a temperature of 170-175 °C, which hinders the flow of physical-chemical processes of hardening. The proposed activities that improve the quality of autoclave processing and precluding the formation of «non-steamings» in the concrete: ensure the temperature inside cellular concrete mass of at least 80 °C before curing, the vacuum (P=‒0.5 Bar) before pressure rise in the autoclave, preventing the ingress of air into the autoclave at the beginning of the process.
Modification of the Hematite Filling Surface of New Composition Material during High Pressure Testing
Authors: Matyukhin Pavel V.
Published: October 2018

The paper presents the results of the researches on structure modifications of the surface of iron-ore hematite concentrate under the pressure up to 20000 MPa with the use of modern research method – scanning electron microscopy. Hematite iron-ore concentrate (hematite) is the filling for the newest composite material which can be used in the domain of nuclear building. Such composite material has the same aluminum containing matrix in its base and it contains significant amount of such filling. This modern composite material can be used for engineer structures that can experience high pressure even in extreme cases (fires, sharp dynamic load and strikes). The images of the surface of hematite particles under the pressure of 5000 MPa, 10000 MPa, 15000 MPa and 20000 MPa were studied.
Slag Technogenic Formations as a Material for the Production of Silicate Products and Pig Iron
Authors: Mikheenkov M.A. , Sheshukov O.Yu. , Lobanov D.A.
Published: October 2018

The EAF and LF slag processing became an actual issue at the present day metallurgy. The possibility of joint and complete utilization of both electric furnace and ladle slag is considered in this paper. The purpose of the work was to develop a method for joint processing of EAF and LF slag with the production of marketable products. A simplex-lattice planning method was used during the work. The raw mixture consisted from EAF slag, ladle slag and limestone. The components of the raw mixture were mixed according to the experimental design, heated and melted under reducing conditions. The phase and chemical composition of melting products, obtained during the experiment, were determined. The results of the experiment showed that both slags and lime can be used together to produce Portland clinker and pig iron. These products are in good agreement with normative documents and thus, they can be used in further production.
Elaboration and Investigation of Metallic Coating with Inclusion of Potassium Polytitanate
Authors: Shcherbakov I.N. , Ivanov V.V. , Korotkiy A.A.
Published: October 2018

The possibility of receiving of compositional Ni-P coating modified by potassium polytitanate was analyzed. An aqueous solution to obtain the composite coatings on the basis of nickel-phosphorus alloy modified by K2О·nTiO2 onto steel details of the friction knots was developed. The complex oxide K2О·nTiO2 represents a layered material from the scaly form nanocrystals with 20-80 nm thick and "diameter" 280 nm. The velocity forming of the modified compositional Ni-P coating was investigated, and the optimal quantity of the introduced potassium polytitanate (8 g/l), as a modified compound into solution, was determined, too. The tribological characteristics and micro-hardness of the resulting coatings depending on the chemical composition of solution and surface state of the rider were investigated.
Reinforced Antifriction Epoxy Fluoroplastics
Authors: Ivanov V.A. , Zakharychev S.P.
Published: October 2018

The materials are antifriction self-lubricating (MAS) based on epoxy fluoroplastics compositions reinforced with various fabrics having increased tribotechnical characteristics under conditions of operation without lubrication, with lubrication or in an aqueous medium. A range of antifriction materials has been developed, as well as the main properties and recommendations for use.
Investigation of the Influence of the Form Factor of Finely Dispersed Carbon Components on the Hydrophobicity of the Surface
Authors: Voznesenskaya Anna A. , Zhdanov Aleksey V. , Kochuev D.A.
Published: October 2018

Coating application is a promising direction of introduction into medical practice. The proposed method is aimed at modifying the surface of various implantable polymer assemblies and parts coming into direct contact with blood. This will prolong the life of the implants in the body. In this paper several variants of carbon fine-dispersed fillers are considered, namely: carbon nanotubes, finely dispersed highly oriented pyrolytic graphite, microspheres of titanium carbide. The coatings were applied by a method that did not require the heating of the polyurethane substrate. In this work, the optimal form factor of the alloying additive was investigated in a polymer (polyurethane) bond applied to the surface of the article.
Stochastic Micro-Meso Modeling of Cross-Ply Composites for Prediction of Softening
Authors: Shabley A.A. , Sapozhnikov S.B. , Shipulin Leonid V.
Published: October 2018

Composites are extensively using in modern industry (aircraft and automobile manufacturing, construction, etc.). Nowadays high-strength and lightweight composite materials, such as FRPs, exhibit elastic and strength anisotropy and deform nonlinearly at high stresses. Also, such materials have small enough failure strain in comparison with metals, and they are drastically more expensive than steel and aluminum alloys. The most important task in the design of structures made of composite materials is the minimization of its weight without loss of strength properties. We presented the method for modeling a UD FRP with randomly arranged fibers at the micro-and meso-level. These two approaches were compared on the problem of the composite panel tension. The selection of the mesomodel mechanical characteristics was based on data of the micro-level model. In the mesomodel, the damage accumulation of middle layer (90° layer) was simulated using the Stochastic Failure criterion (random Mott scatter of layer strength). The calculated curves and data, obtained in micro-and mesomodels, correlate well with each other.
Using the Simplex Design Technique for Optimization of Modes of Burnishing with Ball Tools
Authors: Tyurin A.V. , Galimova N.Ya. , Belyaev A.V.
Published: October 2018

It is advantageous to use the method of surface plastic deformation in order to get high-quality surfaces that meet increased requirements for strength and reliability. For efficient process of surface plastic deformation, it is required to define a set of conditions to provide minimum roughness of a machined surface. The paper addresses the problem of experimental search of optimal burnishing modes using the simplex design to minimize roughness of a machined surface. The significance of variable factor ranking was observed for this technique. A specific set of tests resulted in decrease in the initial surface roughness almost by 15 times in the specimens made of aluminum alloy after burnishing with the steel indenter. It was established that the surface quality was significantly affected by a new factor – angle of indenter contact with the machined surface, which had a damping effect on the machine-fixture-tool-workpiece system. The experiments showed that polished indenter balls significantly lowered the roughness grade of the machined surface under the same conditions.
Study on Surface Layers of Aluminum and Titanium Alloys and Analysis of their Scuff Resistance
Authors: Karzhavin Vladimir V. , Maltsev Lev V. , Bakina Viktoriya V.
Published: October 2018

To reduce the risk of scoring copper or zinc coatings were applied to the samples in molten salts at a temperature of 350-500°C. Using ion sputtering and Auger electron spectroscopy the depth of the surface layers and the grain size in the coating were determined. Samples were plates 0.5-0.7 mm thick made of titanium and aluminum alloys. For copper-coated alloys a coating zone up to 10 μm and a diffuse zone up to 6 μm which is intermediate between the coating and the substrate can be distinguished in the surface layers. For zinc-coated aluminum alloys there is one zone of 5-7 μm which is an aluminum-zinc alloy of variable composition across depth. Thus, a soft metal formed on the surface of the titanium and aluminum alloys when processed in the salt melt is connected to the base metal with metallic bonds. Moreover, the higher the temperature and the longer the holding time in the salt melt, the thicker the coating is. While investigating the score resistance a dependence of the friction moment change on the path travelled to a score appearance was obtained. It has been established that the score resistance of the titanium and aluminum alloys is directly dependent on the inhomogeneity factor which is sharply increased when there is a softer (compared with the base metal) coating on the surface of the metal processed. Experimental stamping-drawing of cups made of the titanium alloy workpieces preliminary copper-coated in the salt melt was carried out. The production cycle was significantly reduced, and the surface quality of the products after the coating removal was high, the scoring was not observed. Thus, the use of soft (compared with the base metal) metal coatings applied in salt melts is promising for titanium and aluminum alloys.
Varying of Oil Consumption of Fluid-Film Bearing’s Surface Layer by Means of Application of Anti-Friction Coatings
Authors: Rodichev Alexey Yu. , Sytin A.V. , Tyurin V.O.
Published: October 2018

Gas flame spraying is the most accessible method of gas-thermal spraying. Pores are formed on the inner surface of the bimetallic fluid-film bearings as a result of the application of anti-friction coating on the steel substrate. The presence of such pores, the "microfibre effect", affects positively on life expectancy of fluid-film bearings. The study of the oil consumption of anti-friction coatings allows recommendation of these coatings for using in the manufacturing process of bimetallic fluid-film bearings.
Structure Formation during Liquid-Phase Sintering of the Diamond-Containing Composites with Sn-Cu-Co-W Binders
Authors: Sokolov Evgeniy Georgiyevich
Published: October 2018

Structure formation of diamond-containing composites with Sn-Cu-Co-W binders has been studied within the range of sintering temperatures of 780–820°C. The specimens were obtained by rolling the paste-like mixtures of metallic powders and diamonds on steel substrates, with sintering performed in vacuum. The structure of the sintered specimens was studied by optical metallography, X-ray diffractometry and electron probe microanalysis. Hardness of the materials was identified by Rockwell method (scale B). It has been found that the process of composites sintering is largely affected by oxide films available on the surface of the powders. In order to obtain composites having less than 10% porosity and up to 96–98 HRB hardness, they have to be sintered at the temperature of 820°C which eliminates the oxide films.
Accelerated Forming on the Sol-Silicate Binder in Precision Casting
Authors: Znamenskii L.G. , Ivochkina O.V. , Varlamov A.S.
Published: October 2018

As a result of the research, the technology of accelerated forming on the sol-silicate binder in precision casting has been developed. It is based on granular materials cladding by the gel-processing catalysts of the sol-silicate binder and on the use of the clad granular materials as the stucco of ceramic coating layers. That allows to achieve a reduction of ceramic molds product cycle of more than 2...2.5 times and strength improvement of 1.4...1.5 times at the temperature of baking. The developed technology allows to improve the quality of ceramic molds and significantly shorten the forming cycle. Production tests of the gel-processing clad stucco in the investment casting showed a significant reduction of the reject precision castings, acceleration of ceramic molds production and a reduction of the working hours on removing "wedged" ceramic from less-accessible cast section cavities of the pump parts from complex alloyed steels.
Features of Steel Tape Deformation-Strength Properties Formation by Plasma-Cavitating Treatment
Authors: Steblyanko V.L. , Ponomarev Anton P.
Published: October 2018

The paper reveals the key features of metal products deformation-strength properties obtained by them as a result of plasma-cavitating treatment. A strengthened cold-rolled tape of steel grade 08ps (Russian State Standard (GOST) 1050-88) was chosen as a model object. Samples of the tape were treated by plasma-cavitating method at certain values ​​of technological parameters (power density and time of plasma action). Then they were tested in accordance with Russian State Standard (GOST) 11701-84. It is determined that the strength of the material remains at the level before processing. At the same time, the percent elongation at break increases essentially (up to 36.3% in relation to the initial indices). It is shown that the dependencies of change in plastic properties of the material on processing time at different values of power density are non-linear with critical points of relative change of percent elongation minimum, due to those physical processes that occur during the treatment period. The location of these critical points depends on both the power density and the time of plasma-cavitating treatment.
Optimal Shape Selection of Heat Exchangers Surfaces during Convective Heat Transfer
Authors: Konukhov V. , Mukhanov S. , Konukhova G.
Published: October 2018

The article contains the results of a research in constructing of modern heat exchangers form of heat exchanging surfaces and modes of heat media flux, providing minimum area (size) of heat exchanging apparatus. Decreasing of heat-transferring area is achieved by using different techniques of intensification of convective heat exchange. Intensification of the heat exchange is accompanied by increasing of energy consumption for pumping the coolant. It is concluded that under the conditions of turbulent flow, the transport mechanism does not strongly depend on the shape of the perturbations introduced into the flow, while the tendency to approach the dependences is common to the curves for the considered surfaces, and the experimental data obtained on pipes with a periodic section of the flow cross-section along the length. Using surfaces creating channels with a greater coefficient of hydraulic resistance when creating a compact heat exchangers, which corresponds to surfaces for which the principle of trans-verse flow is realized.
Experimental Research of Thermo-Hydraulic Separators and Dispatchers in Heat Supply Systems
Authors: Yavorovsky Y.V. , Romanov D.O. , Khromchenkov V.G.
Published: October 2018

This article is concerned with the research of thermos-hydraulic separators and dispatchers (THD) in heat supply systems and focuses on the experimental part of the research. Тhe experiments allowed to develop the ANSYS Fluent model in terms of accuracy and veracity. The developed model allows to predict operation of THD in different regimes. The results may be used for designing the systems with THD. Such systems may be low temperature district heating systems, where THD allow to hydraulically separate the circuits from each other.
Theoretical Description of Electrophysical Properties of Syntactic Carbon Foams
Authors: Fedyaev V.L. , Galimov E.R. , Galimova N.Ya.
Published: October 2018

Syntactic carbon foams represent a new class of advanced composite materials with the ordered structure. They have unique heat transfer, stress-strain, electophysical and other performance properties. Syntactic foams feature a regular structure based on a ratio of solid and gaseous volumes. The paper specifies the area of application for syntactic carbon foams in the various manufacturing sectors. Another promising area for application of carbon foams is related to continuously increasing complexity and improvement of electronic systems for defense and aerospace industries. Electrical resistivity is known as a main electrophysical property of materials, including syntactic carbon foams. The theoretical formulae were derived to calculate the influence of physical chemical properties of initial materials, composition and ratio of mixture components, the method for synthesis of syntactic carbon foams on their conductivity was used. The electrical resistivity of materials can also change significantly according to the operating conditions: ambient temperature, humidity, pollution, mechanical loads, radiation and other factors. That’s why the research that aims at the theoretical description of syntactic carbon foams depending on the above factors is extremely relevant.
Growing of AlInGaAsP Solid Solutions on InP Substrates for Photovoltaic Converters
Authors: Lunin L.S. , Lunina M.L. , Kazakova A.E.
Published: October 2018

The article contains a description of various growing conditions for isoparametric heterostructures based on InP. It is shown that the structural perfection of solid solutions grown on InP substrates is influenced by parameters, such as the temperature of the epitaxy process, the temperature gradient, and the composition and thickness of the liquid zone. By analyzing the quality of the surface and the structural perfection of isoparametric AlGaInAsP solid solutions, based on InP, optimal parameters of the zone recrystallization process in the temperature gradient field (TGZR), at which the epitaxial films had minimal roughness and high crystalline perfection, were found.
Lead Germanate Pb5Ge3O11 Crystal Growth
Authors: Vinnik D.A. , Zhivulin Vladimir E. , Gudkova S.A.
Published: October 2018

Single crystals of lead germanate are obtained by the Czochralski technique. The dimensions of hexagonally shaped crystals are up to 25 × 25 × 5 mm3. According to X-ray diffraction measurements the grown crystals respond to lead germanate Pb5Ge3O11 structure. Curie temperature was also measured.
Low-Energy Ion Technique for Semiconductor Surface Preparation
Authors: Chebotarev S.N. , Irkha Vladimir A. , Mohamed Adnan A.A.
Published: October 2018

We proposed an experimental technique for determining the sputtering yields of two-component semiconductors – gallium arsenide and indium arsenide by low-energy argon ions. It was suggested to measure the volume of a crater formed by inert ions bombarding on the target surface using the method of scanning laser confocal microscopy. It was demonstrated that in the energy range from 100 to 300 eV, the energy dependence of sputtering yields for these materials is practically linear. It is established that the sputtering yields for normal bombardment by argon ions at optimum energy of 150 eV are equal to Y(GaAs) = 0.41 and Y(InAs) = 0.73. It is found that an increase in the etching time of the surface of gallium arsenide and indium arsenide leads to a characteristic transformation of the surface relief. The studies of the sputtering of two-component targets indicate the initial strong non-stechiometry. Etching for a certain period of time leads to an equalization of the concentrations of the sputtered components. It was found that to obtain a uniform composition of the mass flow it is necessary to pre-sputter the targets with shielded substrates.
About Raising of the Gas Vortex Stabilization Efficiency in Plasma Torch for Metal Cutting
Authors: Matushkin A.V. , Pyckin Yu.A. , Anakhov S.V. , Matushkina I.Y.
Published: October 2018

Influence of gas distribution uniformity in the channels of air-gas paths on efficiency and quality of metals cutting is noted for plasmatrons of various updating. It is shown, that application of gas-dynamic filters promotes efficiency and quality of plasmatrons with the one-line scheme of air-gas pathswork. The technique for estimation of gas distribution uniformity in the channels of metal-cutting plasmatron is presented.
Combined Methods of Laser Processing of Steel
Authors: Bakhracheva Yu.S.
Published: October 2018

This article examines the influence of laser heat treatment of nitrocementation steel on the phase composition, structure and hardness of surface layers. It is shown that the combined heat treatment of steels – nitrocementation and laser hardening allows to provide high wear resistance of surface layers of steel.
Influence of Electrode Gap’s Value in Electron Gun on the Penetrating Ability of Electron Beam during the Implementation of Additive Processes
Authors: Gribkov M.S. , Portnov M.A. , Kozhechenko A.S.
Published: October 2018

The urgency of experimental study of the formation of powerful electron beams in technological electron guns is substantiated. The design of a technological electron gun of ELA type is described and the possibility of adjusting the electrode gap for changing characteristics of the beam being formed is shown. A series of experiments on the melting of plates (of steel 30 and titanium alloy VT6Сh (Fe up to 0.4%; C up to 0.1%; Si up to 0.07%; V = 3.5-4.5%; N up to 0.05%; Ti = 87.62-90.63%; Al = 5.5-6.75%; O = 0.07-0.2%; H < 0.01%; other elements up to 0.3%) were carried out, during which the electrode gap was varied. Analysis of obtained macrosections of melting regions is made and conclusions about the effect of magnitude of the electrode gap on the shape and transverse dimensions of melting regions are drawn.
Influence of Technological Parameters of Direct Laser Deposition Process on the Structure and Properties of Deposited Products from Alloy Ti-6Al-4V
Authors: Gushchina M.O. , Klimova-Korsmik Olga G. , Turichin Gleb A. , Shalnova S.A.
Published: October 2018

The technology of direct laser deposition is the most promising for using in various industries. One of the most interesting areas for using this technology is an aviation industry. Due to their unique properties, titanium alloys are widely used in the aircraft industry for gas turbine engine components. In this paper, the effect of DLD process parameters on defect formation and structure is considered. The influence of energy density on the mechanical properties of parts is determined.
Investigation of Grey Cast Iron Microstructure Influence on its Heat Resistance
Authors: Vdovin Konstantin N. , Shubina Marianna V. , Shubin I.G.
Published: October 2018

Grey cast iron is one of the most common engineering materials used to make castings which work in thermal cycling. Under thermal cycling conditions, heat resistance is an important operational property of grey cast iron, which depends to the greatest extent on its structure – size and shape of the graphite inclusions, as well as the metal matrix composition. In this paper, the heat resistance of unalloyed grey cast iron with lamellar and compact graphite distributed in perlitic and perlitic-ferritic metal matrices was determined. The tests were carried out at temperatures of 500 – 800 °C. The results of the studies showed an insignificant difference of perlitic and perlitic-ferritic grey cast iron with lamellar graphite heat resistance. The heat resistance of perlitic ferritic grey cast iron with compact graphite is 16 – 48 % higher than the heat resistance of perlitic ferritic grey cast iron with lamellar graphite. Thus, when the shape of the graphite inclusions changed from lamellar to compact, a significant increase in the heat resistance of unalloyed grey cast iron occurred.
Laser Welded Joints of High-Nitrogen Austenitic Steels: Microstructure and Properties
Authors: Berezovskaya Vera V. , Berezovskiy A.V. , Hilfi D.H.
Published: October 2018

High nitrogen austenitic steels are used as structural materials required possessing high strength and fracture toughness. The present study is concerned with the characteristic features (shape, size, properties and structure) of the laser welded joints in Cr-Mn-, Cr-Mn-Mo-high nitrogen steels compared to the ones of Cr-Ni-steel joint. Butt welded joints were made using carbon dioxide laser with a maximum output of 5 kW in the continuous wave mode. The hardness and tensile tests of welded joints in the air and 3.5 vol.%-solution of NaCl, as well as the theoretical studies were carried out by optical and transmission electron microscopy (TEM). The results are achieved by testing that the welded joints of HNS had satisfactory weldability, adequately high mechanical and corrosion properties. The austenite of the investigated HNS retains high stability throughout the welding cycle.
The Effect of the Operating Speed and Wheel Characteristics on the Surface Quality at Creep-Feed Grinding Titanium Alloys
Authors: Nosenko S.V. , Nosenko V.A. , Koryazhkin A.A.
Published: October 2018

The paper dwells upon flat creep-feed grinding of grooves in Ti6Al4V workpieces. Those were machined with high-porosity silicon carbide wheels of I, H grades at a speed of 20-30 m/s. Machined surfaces were analyzed using a Versa 3D electron microscope. The paper demonstrates the formed morphology of ground surfaces along the workpiece. Higher-speed grinding results in greater concentrations of silicon on the machined titanium alloy surface. Altering the characteristics of the abrasive tool does not have a significant effect on the concentration of silicon on machined surfaces. The paper analyzes how the grade of wheel and the grinding speed affect Ra surface roughness parameter. The article demonstrates the difference in grades of wheels along the surface, at the stage of constant length of arc and the stage of exit.
Electromagnetic Effect of Eddy Currents in Composites with Conductive Components: Magnetic Field Strengthening and its Simple Analytical Estimation
Authors: Sattarov R.R. , Volkova T.A. , Gubaydullin I.Z.
Published: October 2018

Composites and dynamic materials that include conductive components are becoming a suitable choice in different applications. The eddy currents are generated when the conductive components are placed in alternating magnetic field. The eddy currents decrease the primary field and this effect has been well studied and it is used for electromagnetic shielding. Besides, the magnetic field increases in small space near edges of the conductive components. While this effect of magnetic field strengthening is known, it is rarely examined. We will introduce a simple model that can be appropriate for the conductive components in form of long thin sheets. We analytically analyze the model and obtain expressions that give upper bounds for increasing of the net magnetic field. The electromagnetic effect of strengthening should be taken into account when considering an application of the composites. The results are useful for electromagnetic compatibility analysis, non-destructive testing and monitoring of composite and dynamic materials with conductive components.
Numeric Loading Simulation of Titanium Implant Manufactured Using 3D Printing
Authors: Golodnov Anton I. , Loginov Yu.N. , Stepanov Stepan I.
Published: October 2018

The problem of medical implants honeycomb structures loading has been stated. The problem was solved using simulation by the finite element method. Simulation revealed that it is possible to change the elastic modulus of the material more than three times with respect to the bulk titanium alloy. The quality of the simulation was estimated based on the convergence of the simulation data.
Properties of Austenite in Maraging Steel
Authors: Sukhikh Arkadiy A. , Dementyev Vyacheslav B. , Makhneva Tat’ana M.
Published: October 2018

The reasons of high strength of residual and reverted austenite in the maraging steel H18K9M5T are discussed. It has been shown that the high value of the residual austenite yield strength is due to the dispersity of its crystals and phase hardening; a significant increase in the strength properties of the reverted austenite is caused by the presence of intermetallide particles with high dispersity in it.
Strain State during Rolling of Aluminum Samples
Authors: Rekov A.M.
Published: October 2018

The strain intensity as well as the stress-strain state of grains has been experimentally estimated for aluminum sample in strip rolling. The level of correlation between the intensity of deformation and stress-strain state of individual grains in the sample has been calculated. An experimental two-dimensional function of its joint distribution has been constructed. The parameters of two-dimensional function of probability densities have been defined. A relative number of grains with deformation twice as high as the average deformation of the sample has been obtained. The results allow predicting the plasticity exhaustion in individual grains of the sample during rolling and can be used to estimate the likelihood of defects (micro pores and micro cracks) arising during the rolling of aluminum strips.
Effect of Manganese and Magnesium Content and Conditions of Annealing on Mechanical Properties and Cracking Formation during Bending of Aluminum Alloy AA3005
Authors: Tribunskiy A. , Nosova Ekaterina , Aryshenskiy V.
Published: October 2018

The study reveals the effect of Mn and Mg content on mechanical and technological properties during the bending of thin sheets of aluminum alloy 3005. For experimental research the ingots were cast through an out-of-furnace refining unit, homogenized at a temperature of 590°C, during 6 hours. Further ingots were hot rolled to a thickness of 3.5 mm and subsequently cold rolled into sheets of thickness 0.33 and 0.25 mm. Annealing of rolls was provided at temperatures 230...285°C for 1.5 hour in air-circulation annealing furnaces with a protective atmosphere and on a continuous heat treatment line. The change in the tensile strength, yield stress, elongation as a dependence on the content of alloying elements and annealing modes was shown. Technological properties were evaluated by performing bend tests. It has been established that an increased content of magnesium and manganese in the AA3005 alloy results in lower values of the elongation for all annealing temperatures. Annealing in the air-circulation annealing furnaces resulted to higher plasticity values and lower values of strength compared to annealing at continuous heat treatment line for all annealing temperatures and magnesium and manganese temperatures. The plasticity of samples 0.25 mm thick raises evenly throughout the annealing temperature range. For specimens 0.33 mm thick, the effect of the magnesium and manganese content, as well as the type of heat-treatment equipment on the samples’ plasticity during annealing is more pronounced than for samples 0.25 mm thick. In sheet samples from the AA3005 alloy annealed on continuous heat treatment line, with an increased content of magnesium and manganese, cracks are observed at the inflection point for both thicknesses. When annealing in air-circulation annealing furnaces, cracks are not observed for both increased and reduced magnesium and manganese content.
Thermal Cycles and Peculiar Properties of Austenite Decomposition when Laser-Hybrid Welding Steel of K60 Strength Class
Authors: Romantsov A.I. , Fedorov M.A. , Ivanov M.A.
Published: October 2018

Welding is an important technology of joint in engineering structures. In addition to a residual stress influence to a quality of joint, an obstacle in welding analysis are complex phenomena including phase transformation, thermal cycle and microstructure kinetics. The influence appears in microstructure development, formation of defects and in transformation of metallurgy in a welded zone.
This article experimentally defines thermal cycles and shows the results in study of peculiar properties of austenite decomposition kinetics when using the technology of laser-hybrid welding in combination with multiple arc automatic sub-merged welding. There defined the rates of cooling influencing the change of properties of welded joints from tube assortment steel of K60 strength class.
We found that the result of impact of laser-hybrid welding process in a heat-affected zone is that the austenite decomposition in studied steels flows in martensite area generally. The hardness of seam metal and heat-affected zone of the studied steels is of range 350-360 HV, which increases a probability of crack-like, defects formation. We revealed the normative value of hardness, which can be provided if a metal cooling rate in laser-hybrid welding is about 20 °C/s.
Thermal Processes Simulation during Processing Bevel Gears
Authors: Kanatnikov N. , Kanatnikova P. , Pickalov D.
Published: October 2018

In the article the model for forecasting of thermal processes arising during processing of bevel gears is presented. The kinematics of cutting is modeled due to the analytical model. Chipping is modeled using the finite element method. The experiment is based on the method of infrared photography of the cutting process. In the process of carrying out a numerical experiment, the graphs of the heat fields for the tool, the workpiece gear and chips were obtained, and an array of data on their change during the cutting process was achieved. The simulation results showed that the maximum temperatures and heat flows in the tool depend significantly on the choice of the rake and clearance angels of the cutting.
The Influence of Heat Treatment on the Size of the Carbide Inclusions and Hardness of Multilayer Composite Material ZD-0803
Authors: Dildin A.N. , Gerasimov V.Yu. , Trofimov Evgeny A.
Published: October 2018

Technological methods are used to ensure high homogeneity of structure and composition of metals, and thereby to improve operational characteristics and technological properties of tool materials (steels, carbide steels, hard alloys, etc.). At the same time, one of the promising field for improving the technological and operational properties of these materials is the formation of their structural and chemical heterogeneity. The alternation of a large number of layers of steels with different constituents makes it possible to obtain a set of properties that are unattainable for homogeneous steel. The use of modern diffusion bonding technologies has made it recently possible to create a number of new composite materials based on steels with various constituents, and their properties can be used in the manufacture of cutting tools. The purpose of the real work is the study of influence of heat treatment modes on the structure and operational properties of multilayered compositions ZD-0803, produced by LLC "AiR Company". During the study, the structure of the composite material, its hardness and microhardness after annealing and hardening the metal were analyzed. The obtained data show that the studied material has a pronounced layered structure with a sharp transition from one layer to the next one. The technology used in the production of composites provides the practical absence of a transition zone and the absence of such frequent defects of diffusion bonding, as stratifications, pores, oxide inclusions, etc. The study proves that during heat treatment process, the size of the carbides inclusions decreases but their number increases. The work shows that these structural transformations lead to increasing of surface hardness and microhardness of the studied material layers.
Thermomechanical Hardening of Steels
Authors: Shveikin Vladimir P.
Published: October 2018

The methods of the hot working of metals by pressure are discussed. The features of the hot plastic deformation of the metal which determine the formation of the structure and properties of steel are noted. The definition of thermomechanical treatment is given. The definitions of a variety of thermomechanical and high-temperature thermomechanical processes are given. The features of the thermomechanical treatment of steels toughened to martensite are discussed. The temperature, deformation-velocity and time parameters of high-temperature thermomechanical processing are given. Their influence on the structure and properties of steels is analyzed
Using of Smoothed Particle Hydrodynamics Method for Constructing a Mathematical Model of Electron-Beam Surfacing Process
Authors: Shcherbakov A.V. , Rodyakina R.V. , Gaponova D.A.
Published: October 2018

The urgency of the development of mathematical modeling tools that allow calculating the shape of free surface of the melt during the analysis of surfacing processes, introduced in additive production, is shown. A mathematical formulation of the problem is presented, which corresponds to Lagrangian description of liquid medium. It includes equation of motion and energy equation. A numerical algorithm for solving this problem is described, based on Smoothed Particle Hydrodynamics method, and the corresponding equations are given. The analysis of the results of solution of test problems is carried out and comparison of experimental results of the process with well-known data and physical representations is given. The conclusion is made about the possibility of applying this modeling method for development of additive production and creation of automatic control systems for the processes of shaping.
Zero “Background” Line for Iron Alloys Samples Dilatographs Decoding
Authors: Mikhailov S.B. , Mikhailova N.A. , Sharapova Valentina A.
Published: October 2018

The dilatographs decoding variant was carried out on the basis of comparison with the zero "background" line for heating the metallic materials samples. The line is formed taking into account the features of the change in the true values ​​of the linear coefficient of thermal expansion. It has been calculated on the dilatographs basis. The experimental fact was revealed, which is in contradiction with general metal science concepts concerning dilatometric results of recrystallization in materials with polymorphism. The expected result of the thermal change in the sample dimensions has the opposite sign with respect to the experimental result in the recrystallization temperature intervals. This requires careful theoretical and experimental analysis. In our opinion, a possible reason for the discrepancy is the fact that the size of the atoms changes during recrystallization due to the electron orbitals hybridization of iron atoms, due to a change in temperature and intracrystalline pressure.
FEM Simulation of Copper Busbar Pressing on the Continuous Extrusion Line "CONFORM"
Authors: Shimov Georgy V. , Bogatov Aleksandr , Kovin D.
Published: October 2018

Simulation using the DEFORM-3D package of the steady-state pressing mode of a copper busbar on the continuous extrusion line "Conform" was carried out. The nature of the metal flow in the deformation zone was studied. An analysis of the velocities of the metal flow in the prechamber was performed. It was shown that in the channel of the wheel there is pressing out, which negatively affects the quality of the finished busbars and can lead to such defects as "lamination".
Constructing Isotherms of Oxygen Solubility in the Liquid Metal of the Cu-Na-K-O System
Authors: Samoilova Olga V. , Makrovets Larisa A.
Published: October 2018

The thermodynamic modeling of phase equilibria in the liquid metal of the Cu–Na–O, Cu–K–O and Cu–Na–K–O systems in the temperature range of 1100–1300 °С was done. The calculations were performed using the methodology of constructing a surface of component solubility in the metal melt, which does not only allow us to calculate the isotherms of oxygen solubility in the molten metal, but also to link the changes in the composition of such molten metal with quality changes in the composition of the interaction products. The isotherms of the oxygen solubility in the liquid metal of the Cu–Na–O, Cu–K–O and Cu–Na–K–O systems were constructed.
Development of the Algorithm for Determination of Mechanical Properties of Steel 20 with Different Levels of Cumulative Fatigue Damage with the Application of Compact Samples
Authors: Hasanov R.N. , Valiev A.S. , Kuzeev I.R.
Published: October 2018

Nowadays, a change of material properties is evaluated on the basis of the results of "traditional" methods (for example, tensile testing and impact bending test). Unfortunately, "traditional" mechanical testing requires quite large samples, that leads to a damage of studied objects integrity. That is why testing with the application of compact samples, which allows converting obtained results into regular parameters, such as tensile properties and fracture resistance, was developed. Due to the novelty of this method, influence of different factors on testing results is understudied. Here arises the aim to study the influence of the level of accumulated damage on testing results. Regular changes of small punch testing tensile diagrams, depending on the number of worked out cycles, are under study in the present paper. Based on the study results, algorithm for determination of mechanical properties of steel 20 with different levels of cumulative fatigue damage with the application of compact samples was developed.
Impact of High-Frequency Vibrations on Metal Items Resistance to Cyclic and Axial Loads
Authors: Kuzeev I.R. , Naumkin E.A. , Pankratiev S.A. , Tlyasheva R.R.
Published: October 2018

It was shown that the forced vibrations of objects on resonance frequencies could significantly change resistance of these objects to cyclic loads in a low-cycle loading range and decrease critical compression load under axial compression. We carried out a procedure of fatigue testing performance with simultaneous application of high-frequency vibrations. We developed and produced a device allowing carrying out testing aimed to check shape stability of cylindrical shells and their resistance to forced vibrations. Dependence of fatigue life capability within the low-cycle range on the frequency of applied forced vibrations in four harmonics of resonance frequency was experimentally determined. Fatigue life capability decreased by 1,6 times. Decrease of life capability particularly occurs on frequencies which are presumably connected with minimum in size elements of hierarchy of polycrystalline material structures. It was found out that the forced vibrations on resonance frequency contribute the increase of a number of vibrations, that leads to decrease of critical axial compression force value. Decrease can be by up to 40%. Experimental determination of critical load during application of vibrations allowed obtaining formula for adjusting factor calculation in the formula for permitted compression force calculation.
Effect of Superheat Melt Treatment on Microstructure and Mechanical Properties of Aluminum Alloys Produced by Lost Foam Casting
Authors: Deev Vladislav , Prusov Evgeny , Ponomareva K.
Published: October 2018

The resource-saving technology for producing of thin-walled castings from A356.1, A413.1 and A360.0 aluminum alloys by the lost foam casting method, as well as the results of this technology implementation in production conditions are considered in the paper. The technology involves thermo-speed treatment of the melt with the predominance of secondary materials in charge (85...90 wt.%), including isothermal holding and subsequent rapid cooling of the melt for fixation the high-temperature state. It is shown that the use of thermo-speed treatment promotes the production of aluminum castings with fine-grained microstructure and the enhanced level of mechanical properties without the addition of costly modifying additives, and makes it possible to use an increased amount of secondary charge materials during smelting.
Induction Heating Technology for Steel Wire Processing
Authors: Barankova Inna I. , Mikhailova Uliana V. , Kalugina Olga B.
Published: October 2018

This article discusses the induction heating application features in metallurgical industry for previously unused objects, such as wire coils and wire rod bundles. The analysis of international trends and a forecast of the induction heating application shows a steady expansion of the induction technologies in the metallurgical industry. The article considers the advantages of induction heating in comparison to other competitive technologies. Heat treatment in electrotechnological induction plants is determined by the interconnected electric and thermophysical processes taking place in them, the complex nature of the internal heat sources distribution, the dependence of the distribution pattern of the induction plant on the temperature of the products being processed. It is shown that the investigation results of the induction heating method influence the temperature and time factors in the formation of the structure, the increase in the uniformity of heating, and the quality of the heat treatment of steel wire and wire rod buntle, taking into account the stated technological task. The efficiency estimation of application of medium and high-frequency induction heating of steel wire of various diameters is given. Evaluation of the efficiency improving of the induction heating device, when the heat treatment simultaneous multiple strands of steel wire of equal diameter, united in a bundle, is given.
Structure and Stability of Intermediate (Fe, Cr)7C3 Carbides
Authors: Sobolev A.N. , Mirzoev A.A. , Mirzaev D.A.
Published: October 2018

The paper presents a systematic approach to calculate the structure and stability of intermediate (Cr, Fe)7C3 carbides in hexagonal and orthorhombic phases within the framework of density functional theory. It was shown, that the formation energy of the system changes non-monotonically with chromium concentration; the fact is consistent with thermodynamics. It was found, that some intermetallic carbides in the system are more stable than binary counterparts.
Rheological Properties and Substantiation of Hot Rolling Regimes of Low- and Medium Carbon Structural Steels
Authors: Gladkovsky Sergei , Potapov A.I. , Salikhyanov Denis Rinatovich
Published: October 2018

In this paper the authors present the results of a study of plasticity and deformation resistance of the number of structural steels at temperatures of hot rolling. The patterns of changes in the studied characteristics of steels in the range of rolling temperatures are determined. In order to improve the quality of rolled products, we developed and substantiated recommendations for optimizing temperature of rolling ingot of the studied steels. The proposed recommendations have been verified by computer simulation of rolling high billets in flat rolls after heating up to 1100 and 1200 °C. For example, we showed the distribution of strains and stresses throughout the volume of the rolled product from steel grade 38KhS (State Standard GOST 4543-71).
Strength of SHS Aluminium Cast Iron from Dispersed Mechanical Engineering Waste
Authors: Kharisov L.R. , Safronov N.N. , Safronov G.N.
Published: October 2018

The article presents an alternative method of obtaining aluminium cast iron in the process of self-propagating high-temperature synthesis from disperse waste of machine-building enterprises. The deficiencies of the traditional methods for obtaining structural iron castings with aluminum are established. The analysis of the factors influencing the strength of the SHS aluminium cast iron, the planned experiment for obtaining the maximum strength of SHS aluminium cast iron for two input factors varying at three levels and three parallel observations were carried out. The statistical processing of experimental results is performed. The mathematical model is obtained for the dependence of operational factors on the composition of the charge of the SHS process. The significance of the regression coefficients of the equation is determined. The adequacy of the obtained equation is checked for the results of observations. The analysis of the conditions for the formation of the microstructure of aluminium cast iron in the process of SHS-casting is presented.