Metal Working and Material Science最新文献

{"title":"Influence of dynamic characteristics of the turning process on the workpiece surface roughness","authors":"V. Gvindjiliya, Evgeniy Fominov, Denis Moiseev, Ekaterina Gamaleeva","doi":"10.17212/1994-6309-2024-26.2-143-157","DOIUrl":"https://doi.org/10.17212/1994-6309-2024-26.2-143-157","url":null,"abstract":"Introduction. The formation of the surface of a part when processing it on a metal-cutting machine is based on properly selected cutting modes. Complex methods of ensuring the specified quality of the part surface also take into account the tool geometry, its condition, and include corrections for tool deviation from the trajectory set by the CNC system under the influence of kinematic disturbances and spindle wavering. Subject. The paper analyzes the relationship between cutting modes and dynamic characteristics of the turning process, and its mapping into surface roughness. The aim of the work is to evaluate the influence of technological cutting modes taking into account the vibration activity of the tool on the roughness of the machined surface by means of simulation modeling. Method and methodology. Mathematical simulation of the dynamics of the cutting process is given, on the basis of which a digital simulation model is built. A methodology of using the simulation model for determining optimal cutting modes and predicting surface roughness taking into account tool vibrations is proposed. By means of experiments and analysis of the frequency characteristics of tool vibrations, the created model is validated, parameters of the cutting forces model subsystem and dynamic tool subsystem are specified, and geometrical topologies of the part surface are constructed. The calculated cutting forces are compared with experimental forces, and similar patterns and levels of characteristics are observed. An assessment of the optimality of the selected cutting modes is proposed based on the analysis of the tool vibration spectrum relative to the workpiece and the results of the numerical model simulation. Results and Discussion. A comparison of the results of digital modeling of the geometrical surface of the workpiece and the real surface obtained during the field experiment is given. It is shown that the roughness of the real surface obtained by machining with constant cutting modes varies relative to the surface roughness of the simulation model within the limits of not more than 0.066 µm.","PeriodicalId":502919,"journal":{"name":"Metal Working and Material Science","volume":" 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141375050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigations on ultrasonic vibration-assisted friction stir welded AA7075 joints: Mechanical properties and fracture analysis","authors":"V. Gaikwad, S. Chinchanikar","doi":"10.17212/1994-6309-2024-26.2-6-22","DOIUrl":"https://doi.org/10.17212/1994-6309-2024-26.2-6-22","url":null,"abstract":"Introduction. Joint efficiency and strength, particularly in aluminum alloys, are crucial in aerospace, defense, and industrial applications. Post-welding treatments like shot peening and laser shock peening significantly improve joint efficiency and strength, enhancing fatigue life, grain structure, and tensile strength. The purpose of the work. The literature reviewed shows that the ultrasonic vibration-assisted friction stir welding (UVaFSW) and post-weld treatment improved the mechanical properties and material flow. However, limited studies have been observed on the UVaFSW joints of AA7075-T651, considering the consequence of welding speed, tool rotation, and post-weld shot peeing treatment. The methods of investigation. The study investigates the ultrasonic vibration-assisted friction stir welded (UVaFSwed) AA7075-T651 joint's tensile strength, microhardness, microstructure, and fracture behavior, considering the impact of tool rotation, welding speed, and post-weld shot peening treatment. Results and Discussion. The post-weld treated shot-peened UVaFSWed joints demonstrated the maximum tensile strength of 373.43 MPa, the microhardness of 161 HV, and the lowest surface roughness of 15.16 µm at 40 mm/min welding speed when compared to the friction stir-welded (FSWed) joints. These results indicate that shot peening improved the mechanical properties and surface quality of the UVaFSWed joints. The high tensile strength and low surface roughness make these joints suitable for applications requiring strength and aesthetics. The fracture for the shot peened UVaFSWed joints mainly occurred in the heat-affected zone (HAZ) during the tensile test. It could be attributed to the higher temperature experienced during welding, which resulted in grain growth and decreased material strength in the HAZ. The shot-peened UVaFSWed joint has a more uniform grain distribution than the FSWed one, which contributed to the joint's higher tensile strength. The fractured surface of the shot peened UVaFSWed joints showed larger, equiaxed, and shallow dimples, resulting in higher ultimate tensile strength (UTS) and microhardness compared to the conventional FSWed joints. The mechanical properties and microstructure observed in the welding zones of shot peened UVaFSWed joints are superior to those of conventional FSW joints. However, further investigation is required to determine the specific factors contributing to this localized failure at HAZ, considering the effects of shot peening parameters. This study also suggests the potential for optimizing shot peened UVaFSWed joints of AA7075-T651.","PeriodicalId":502919,"journal":{"name":"Metal Working and Material Science","volume":" 28","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141371714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of Fe-matrix composites with carbide strengthening, formed by sintering of iron titanides and carbon mechanically activated mixtures","authors":"G. Pribytkov, A. Baranovskiy, I. Firsina, Kirill Akimov, Vladimir Krivopalov","doi":"10.17212/1994-6309-2024-26.2-212-223","DOIUrl":"https://doi.org/10.17212/1994-6309-2024-26.2-212-223","url":null,"abstract":"Introduction. The addition of dispersed solid particles of refractory compounds (carbides, borides, silicides) to the structure of alloy is a widely used effective way to increase the wear resistance of steels and alloys. Composites with a matrix of iron-based alloys (steel and cast iron) strengthened by titanium carbide particles are of great practical interest. The main structural characteristics, which define hardness and wear resistance of the composites, are volume fraction, dispersion and morphology of the particles of the strengthening carbide phase. The structure of composites depends on the method of its preparation. The methods of powder metallurgy combined with preliminary mechanical activation of powder mixtures have become widespread. It is previously established that in mechanically activated powder mixtures of FTi35S5 ferrotitanium, consisting of 82 % of (Fe,Al)2Ti phase, and P-803 carbon black, a reaction occurs with the formation of a composite consisting of a steel binder and titanium carbide. The synthesis reaction of carbides occurs in a solid-phase mode at combustion’s temperatures of 900–950 °C. Therefore, there is no coarsening of the structure due to the growth of carbide particles, which is typical for reactions in the presence of a liquid phase. FTi35S5 alloy contains a plenty of impurities (silicon, aluminum and etc). The purpose of the work is to investigate the phase composition and structure of the products of the interaction of Fe2Ti and FeTi iron titanides with carbon under the conditions of reaction sintering of mechanically activated powder mixtures and to determine the possibility of synthesizing iron-matrix composites strengthened with submicron titanium carbide particles. Research methods. The structure and phase composition of sintered compacts from mechanically activated powders were studied by optical metallography, X-ray diffraction (XRD) and scanning electron microscopy (SEM) using determination of the elemental composition by energy-dispersive X-ray spectroscopy (EDX). Experimental technique. The reaction mixtures were prepared using intermetallic powders obtained by vacuum sintering of compacts from iron and titanium powder mixtures of 2Fe+Ti and Fe+Ti compositions. Carbon black was added to the intermetallic powders to convert all the titanium containing in the intermetallic compounds into carbide. The titanides – carbon black mixtures were processed by an Activator 2S planetary ball mill for 10 min milling time at a rotation speed of 755 rpm (40g). The mechanically activated mixtures were cold compacted into cylindrical samples with a diameter of 20 mm, which were sintered in vacuum at а temperature of 1,200 °C and an isothermal holding time of 60 minutes. Results and discussion. According to the results of X-ray diffraction analysis, almost all titanium contained in iron titanides reacts with carbon to form carbide and reduced iron. The sintering products of compacts of both compositions contain targ","PeriodicalId":502919,"journal":{"name":"Metal Working and Material Science","volume":" 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141371888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of coatings with high infrared emissivity","authors":"Vyacheslav Sirota, Sergei Zaitsev, Mihail Limarenko, D. Prokhorenkov, M.S. Lebedev, A. Churikov, Alexey Dan'shin","doi":"10.17212/1994-6309-2024-26.2-23-37","DOIUrl":"https://doi.org/10.17212/1994-6309-2024-26.2-23-37","url":null,"abstract":"Introduction. One of the promising modern methods of coating formation is detonation gas dynamic sputtering. Coatings obtained by this method have high adhesion to the substrate, dense structure and specified functional properties. Development of technology for obtaining functional coatings with high emission coefficient in the infrared range is an urgent need for the development of high-temperature industrial processes and technologies. High-temperature industrial processes consume a large amount of energy, so improving the energy efficiency of industrial equipment is considered as one of the ways to overcome the ever-growing energy crisis. To this end, coatings with high infrared emissivity have been developed for industrial furnaces. These coatings are usually applied to the furnace walls, which significantly improves energy efficiency by increasing heat transfer from the heat-emitting surfaces of the furnace. The purpose of the work is to obtain coatings with high emission indices in the infrared range for further recommendation of its use in baking ovens of Shebekinsky machine-building plant. Methods for studying coating specimens obtained by detonation gas-thermal method: scanning electron microscopy, X-ray phase analysis, energy dispersive analysis, infrared spectroscopy. Results and discussion. The microstructure, phase composition, emissivity and thermal cycling resistance of Fe2O3; Al2O3 + 10 % Fe2O3; Ti + 10% Fe2O3 coatings obtained by detonation gas-dynamic powder spraying are investigated in this work. The results of the study showed that the obtained coatings have a dense structure, increased emissivity and resistance to thermal treatment cycles, as a result of which the structure of the crystal lattice of the coatings does not change.","PeriodicalId":502919,"journal":{"name":"Metal Working and Material Science","volume":" 36","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141372727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of evolution of microstructure and mechanical properties in aluminum alloy 1570 with the addition of 0.5 % hafnium","authors":"Igor Zorin, E. Aryshenskii, Aleksandr Drits, Sergey Konovlov","doi":"10.17212/1994-6309-2024-26.1-113-128","DOIUrl":"https://doi.org/10.17212/1994-6309-2024-26.1-113-128","url":null,"abstract":"Introduction. Aluminum alloys are in high demand with the aerospace industry. From the viewpoint of various performance characteristic combinations, high-magnesium aluminum alloys with the addition of transition metals, such as Zr and Sc, are among the most future-oriented alloys. Alloy 1570 is one of the most popular in this group. Recent studies demonstrated the positive effect of 0.5 % hafnium addition on as-cast structure. Study objective is to study the effect of the addition of 0.5% hafnium on the structure and properties of aluminum alloy 1570 during thermomechanical treatment. The study addresses the effect of cold rolling, homogenization, and recrystallization annealing on mechanical properties and microstructure of the specimens from alloy 1570 and similar alloy with 0.5 wt. % hafnium addition. Study methodology: for the study, ingots were cast from alloy 1570 with and without additions of 0.5 wt. % of hafnium. The resulting ingots were homogenized for 4 h at 440 °С, followed first by hot rolling and then cold rolling. Cold-rolled specimens were annealed at temperatures 340 °С to 530 °С with a holding time of 3 hours. The homogenized, cold-rolled, and annealed specimens were examined using transmission and light microscopy. In addition, homogenized and cold-rolled specimens were subjected to uniaxial tensile tests to determine the mechanical properties of the studied alloy. Results and discussion. It is revealed that in an alloy containing hafnium, after homogenization annealing, there is a slight decrease in the average particle size and an increase in its total proportion in comparison with alloy 1570. In general, 0.5 % hafnium addition does not significantly affect the mechanical properties. The number of nanoparticles in both alloys increases, as does the yield strength compared to the as-cast state. When heated, both alloys demonstrate an increase in plasticity and a decrease in strength characteristics. Studies of the annealing effect on the grain structure of the studied alloys showed that hafnium increases the tendency of alloy 1570 to recrystallize. However, additional research is required to determine the reasons for this phenomenon.","PeriodicalId":502919,"journal":{"name":"Metal Working and Material Science","volume":"21 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140239038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptation of the CNC system of the machine to the conditions of combined processing","authors":"Mikhail Borisov, D. Lobanov, Alexander Zvorygin, V Yu Skeeba","doi":"10.17212/1994-6309-2024-26.1-55-65","DOIUrl":"https://doi.org/10.17212/1994-6309-2024-26.1-55-65","url":null,"abstract":"Introduction. Increasing the efficiency of processing technologies for products made from modern high-strength, difficult-to-process materials with increased physical, mechanical and operational properties consists not only in improving the technology itself, the tools for its implementation, but also in modernizing technological equipment taking into account new achievements in the field of mechanical engineering. Modern computer numerical control (CNC) equipment is now quite advanced in terms of controlling basic cutting movements. Adaptive monitoring and control systems, as a rule, additionally installed on processing equipment, make it possible to further improve the quality of processing parameters. With the development of new hybrid and combined technologies that combine several types of influence on the product being processed, the issue of synchronizing the automatic control of the movements of parts of technological equipment with the control and management of accompanying processes of combined technologies has become acute. One example of such technologies is electrochemical diamond grinding with periodic dressing of the working surface of a diamond wheel using reverse polarity current. The polarity of the current and the duration of its pulses are controlled by special programmable devices. Current switching units are connected to it. It serves to supply alternating currents of direct and reverse polarity to the electrical circuit and is made on the basis of key elements. Installing such programmable devices on CNC machines leads to its’ equipping with an additional autonomous automatic control system. At the same time, it is difficult to coordinate the operation of the machine’s CNC system, which controls the movements of its working parts, and the programmable device used to control the polarity and duration of current pulses during combined processing. The purpose of the work is to synchronize the CNC system of the machine with the control system for the process of periodically changing the polarity of the current. The study was carried out on an experimental stand. Methods. The research methodology involved conducting an experiment consisting of synchronizing the operation of the machine’s CNC system with the operation of the control system for the process of periodically changing the polarity of the current. To evaluate the results, the time of movement of the diamond wheel as a result of the working stroke was compared with the duration of current pulses of different polarities specified in the control program of the developed software. Results and discussions. As a result of the research, it is established that the developed software and hardware complex makes it possible to synchronize in the CNC system of the machine tool the control of the movements of the working parts with automatic control of the periodic change of current polarity during electrochemical diamond grinding, which can significantly expand the technical capabi","PeriodicalId":502919,"journal":{"name":"Metal Working and Material Science","volume":"14 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140240690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Features of calculating the cutting temperature during high-speed milling of aluminum alloys without the use of cutting fluid","authors":"D. Gubin, A. Kisel’","doi":"10.17212/1994-6309-2024-26.1-38-54","DOIUrl":"https://doi.org/10.17212/1994-6309-2024-26.1-38-54","url":null,"abstract":"Introduction. The calculation of temperature during high-speed milling of aluminum alloys is of interest, since temperature can act as one of the main limiting factors in choosing rational milling modes. This is especially important when milling thin-walled products used in aircraft construction, since its high values can lead to local warping of the structure. It is not possible to control the temperature factor in production conditions, which makes it necessary to develop a mathematical model for calculating temperature. The purpose of the work is to develop a methodology for predicting the cutting temperature during high-speed milling of aluminum alloy workpieces for cutting conditions, in which it is not possible to use cutting fluid. Methods. This paper presents experimental studies of the cutting temperature during high-speed milling of aluminum alloy workpieces without the use of cutting fluid using non-contact temperature measurement methods. The results obtained were used to determine the coefficients substituted into formulas for calculating temperatures on the front and back surfaces of the cutting blade. Results and discussions. Based on the results of experimental tests and theoretical modeling, a temperature graph is drawn up. A comparison of experimental studies of milling of aluminum alloy D16T, with changing cutting conditions (the cutting speed changed) with theoretical data, gave a satisfactory result. The average relative error when comparing experimental data with theoretical one is 6.05 %. Based on experimental data, it can be concluded that the comparison of experimental data for measuring cutting temperatures is in satisfactory agreement with the proposed method of theoretical calculation of temperatures. The advantage of this technique is that it allows, without time-consuming and costly experimental studies, theoretically calculate (forecast) the temperatures on the front and back surfaces of the cutting blade, as well as the cutting temperature, for those narrow milling conditions, where effective heat removal from the cutting zone is impossible. It can also be used for milling aluminum alloys, the mechanical and thermophysical properties of which differ.","PeriodicalId":502919,"journal":{"name":"Metal Working and Material Science","volume":"5 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140238995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi empirical modeling of cutting temperature and surface roughness in turning of engineering materials with TiAlN coated carbide tool","authors":"Nilesh Patil, A. Saraf, Atul Kulkarni","doi":"10.17212/1994-6309-2024-26.1-155-174","DOIUrl":"https://doi.org/10.17212/1994-6309-2024-26.1-155-174","url":null,"abstract":"Introduction. In manufacturing, obtaining a specified surface roughness of the machined components is of great importance to fulfill functional requirements. However, this is significantly affected by the heat generated during processing, potentially causing variations in dimensional accuracy. The surface roughness significantly affects the fatigue performance of the component, while the cutting tool's lifespan is dictated by the generation of cutting temperatures. The purpose of the study is to create semi-empirical models for predicting surface roughness and temperature of different work materials. Improved cutting performance is achieved by precisely determining the cutting temperature in the zone being machined. However, calculating the cutting temperature for each specific case is fraught with difficulties in terms of labor resources and financial investments. This paper presents a comprehensive empirical formula designed to predict both theoretical temperature and surface roughness. The methodology. The surface roughness and temperature values were evaluated for EN 8, Al 380, SS 316 and SAE 8620 materials using TiAlN coated carbide tool. The TiAlN coating was formed using Physical Vapor Deposition (PVD) Technique. The response surface methodology was used to prepare predictive models. Cutting speed (140 to 340 m/min), feed (0.08 to 0.24 mm/rev) and depth of cut (0.6 to 1.0 mm) was used as input parameters for measuring the performance of all material in terms of surface roughness and cutting temperature. The tool-work thermocouple principle was used to measure the temperature at the chip-tool interface. A Novel Calibration Setup was developed to establish a connection between the electromotive force (EMF) generated during machining and the cutting temperature. Results and Discussion. It is observed that the power required for machining was largely transformed into heat. The highest cutting temperature is recorded when machining of SS 316 followed by SAE 8620, EN 8. However, low temperature is reported during machining of Al 380 and it is mainly governed by the thermal conductivity of the material. The lowest surface roughness is observed in SAE 8620, EN 8 material followed by SS 316 and Al 380. Semi-empirical method and regression model equations show a good agreement with each other. Statistical analysis of nonlinear estimation reveals that the cutting speed, feed, and density of the material have a greater effect on surface roughness, whereas the depth of cut has a greater effect on temperature generation. The study will be very useful for predicting industrial productivity when machining of EN 8, Al 380, SS 316 and SAE 8620 materials with TiAlN-coated carbide tool.","PeriodicalId":502919,"journal":{"name":"Metal Working and Material Science","volume":"13 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140241035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on the electrical discharge machining of cryogenic treated beryllium copper (BeCu) alloys","authors":"Dhruv Sawant, Rujuta Bulakh, V. Jatti, S. Chinchanikar, Akshansh Mishra, Eyob Messele Sefene","doi":"10.17212/1994-6309-2024-26.1-175-193","DOIUrl":"https://doi.org/10.17212/1994-6309-2024-26.1-175-193","url":null,"abstract":"Introduction. In modern manufacturing world, industries should adapt technological advancements for precision machining of difficult-to-machine metals, especially for beryllium copper (BeCu) alloys. The electrical discharge machining of alloys has proven its viability. The purpose of the work. A literature review indicated that the investigation of electrical discharge machining of BeCu alloys is still in its infancy. Furthermore, the cryogenic treatment of workpieces and electrodes in electrical discharge machining has not received much attention from researchers. Moreover, the impact of magnetic field strength on surface integrity and productivity during electrical discharge machining has not attracted much attention from researchers. The methods of investigation. This paper describes the use of electrolytic copper with different gap current values, pulse on periods, and external magnetic strength for electrical discharge machining of BeCu alloys. This paper examines how the material removal rate, the thickness of the white layer, and the formation of surface cracks are affected by cryogenic treatment of the workpiece and tool, pulse-on time, gap current, and magnetic strength. Results and Discussion. The combination of the cryogenically treated BeCu workpiece and the untreated Cu electrode had the highest material removal rate among all the combinations of workpieces and tools used in this study. The pulse on-time and the strength of the magnetic field had little influence on material removal rate, whereas the gap current had the greatest effect. The maximum achieved material removal rate was 11.807 mm3/min. At a high material removal rate, the observed thickness of the white layer on the horizontal surface ranged from 12.92 µm to 14.24 µm. In the same way, the maximum and minimum values for the vertical surface were determined to be 15.58 µm and 11.67 µm, respectively. According to scanning electron microscopy, the layer thickness was less than 20 µm, and barely noticeable surface cracks were observed in specimens with low, medium and high material removal rates. Obviously, due to the cryogenic processing of the workpiece and the external magnetic strength, there was a slight cracking of the surface and the formation of a white layer.","PeriodicalId":502919,"journal":{"name":"Metal Working and Material Science","volume":"66 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140237388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis of the heddle drive mechanism","authors":"Yuriy Podgornyj, V Yu Skeeba, T. Martynova, D. Lobanov, N. Martyushev, Semyon Papko, Egor Rozhnov, Ivan Yulusov","doi":"10.17212/1994-6309-2024-26.1-80-98","DOIUrl":"https://doi.org/10.17212/1994-6309-2024-26.1-80-98","url":null,"abstract":"Introduction. Domestic enterprises in various industries use a variety of process equipment, including weaving machines. Modern weaving machines have several unique features, including a close relationship between technical condition, productivity, and product quality. Weaving machines are widely used in the textile industry in Russia and other countries. To produce cotton, silk, wool, linen, and other types of fabrics, appropriate machines are designed, including shuttle, shuttleless, pneumatic, and hydraulic machines. One of the most crucial parts of the machine is the heddle lifting mechanism, which determines the weave pattern and the quality of the fabric produced. The purpose of the work is to reduce the dimensions of the loom by changing the design parameters of the heddle lifting mechanism. The research methods are based on the theory of machines and mechanisms. They enable the development of a method for synthesizing the heddle lifting mechanism and designing a device with reduced dimensions. The paper presents the synthesis and analysis of the Assur group algorithm, which can determine the kinematic characteristics of the mechanism. Results and discussion. Following the proposed methodology, the mechanism design was modified by removing the fixing device from the lever mechanism operating area. This allowed for a reduction in interaxial distances and a change in the kinematic scheme. As a result of the new position of the fixed axes, some levers, the connecting rod, and the angle of the double-arm lever were also altered. The synthesis of the mechanism is proposed to begin with the last Assur group, setting it a specific value for the G-point motion equal to 75 mm. (motion of the fourth heddle shaft). As a limitation, the equality of arcs (chords) E´E = F´F ` was accepted. By assigning these values to the input element for the second-class first-type Assur group and bearing in mind the accepted conditions, the motions for point D were obtained. Thus, the value of the swing angle  of the roller shaft equal to 22.46° was obtained, which is 27.44 mm along the chord. Applying the interpolation principle, we found the initial motion value of 28 mm. Since the loom is planned to produce interlacing fabric patterns using 10 heddles, the design provides for a variable parameter that allows changing the motion of the heddles depending on their location in the depth of the machine. This role was assigned to the lever B03D. A cam pair synthesis was performed after determining the maximum and minimum values of the center of the roller motion. In total, 5 types of laws of motion were considered: straight-line, harmonic, double harmonic, power-law, cycloidal ones. For the center of the roller, the cycloidal law of motion was selected since it better corresponds to the specified conditions. The synthesis's accuracy was confirmed by the constructed cam profile and conducted kinematic studies for the Assur groups.","PeriodicalId":502919,"journal":{"name":"Metal Working and Material Science","volume":"1 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140239130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}