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The object of research is geometric models of the process of incremental forming of parts from sheet material. The subject of research is a graphical model for finding the optimal values of the parameters of the forming process based on multidimensional descriptive geometry. The author of the article discusses the main optimizing factors and process parameters. Particular attention was paid to the problems of constructing geometric models for determining the optimizing factors for incremental forming. The research method is a way of constructing a graphical optimization model of the process using the projection drawing of Radishchev for multidimensional space. Mathematical modeling was also applied to check the correctness of the obtained optimal parameters.

Aim of the work was obtaining of the composite in form of n-layer polymer film and investigation of the structure. Manufacturing of the film combine the advantages of individual layers in one production process to achieve multilayer composite. In the experiment LDPE was used as main material. Processing of material was done using blow molding process and final product was obtained if the form of thin film. Conventional blown film line contains one extruder, die head, cooling ring and calibration basket, collapsing frame and winding rolls. To develop structure unique blow film line has been used. Two another extruder were joined to existing one transferring material simultaneously to the die head where 3 materials were joined together to combine 3-layered film. This process gives possibility to design final product and control the structure in many various combinations.

The objective of this paper is to investigate the fuel injection system in diesel engines by using inline pumps. In a diesel engines, the fuel injection pressure plays an important role in the combustion process in order to obtain high performance and low fuel consumption. The experiments in this paper are been performed on a 6 cylinder inline pump which is actioned by an electric motor with variable r.p.m.-s The quantity of the fuel injected by each injector is measured function of time and the speed of electric motor. The experiments show the degree of non-uniformity of the fuel delivered by the pump to injectors.

This research addresses attention to human upper limb experimental analysis during feeding process aiding disabled persons. The research core is focused on the experimental process of obtaining the angular amplitudes and trajectories developed by the human upper arm during feeding process. The research originality consists on the obtained results which can be used in further researches for command and control of robotic assisting devices.

The paper investigates the technology of production of steel billets continuously cast billets for rolling balls of large diameter. In Kazakhstan, in connection with the development of new copper deposits such as Aktogay and Bozshakol, the need for large diameter steel grinding balls for primary ore processing has increased. The main problem in the operation of large diameter grinding balls is the tendency of the grinding media to break during operation. The authors of the work investigated the process of production of steel billets continuously cast billets with a cross section of 150 × 150 mm for rolling balls of large diameter (d 125 mm) in the PB LLP "KSP Steel", which showed that the breaking of grinding balls is initiated mainly by the presence of internal discontinuities (gas axial looseness) in continuously cast billets. Studies have shown that the technological scheme for the production of grinding balls with a diameter of 125 mm from continuously cast billets with a section of 150 × 150 mm, including steel smelting in an arc furnace with steel finishing on a ladle-furnace unit, deoxidation with aluminum and degassing in a ladle vacuum apparatus, casting steel in a closed jet on a continuous casting and further production of rolled stock on a rough rolling mill ensures the absence of internal discontinuities (gas bubbles, axial looseness) in the workpieces and ensures the production of high quality balls.

A truck's gearbox friction rings restoring process by hot 3D stamping was developed and adopted for implementation. Using this recovery method in combination with subsequent synchronizer rings mechanical processing allows restoring up to 95% resource of worn parts. It was established that section of a stamp's deforming element for axisymmetrical parts restoring should be a one-way wedge with a sloping face facing the reconstructed surface. The most significant factors influencing the transmission gearbox synchronizer rings restoring process are: stamp deforming element thickness, plunging depth and distance to a recoverable surface. The energy and force parameters study of hot plastic deformation process serves as input data for automatic design systems of working elements of stamps for restoring synchronizer rings as well as for determination of a required deforming force during hot stamping.

The article focused on the influence of part orientation on the surface roughness of cuboid parts during the process of fabricating by FDM technology. The components, in this case, is simple cuboid part with the dimensions 15 mm x 15mm x 30 mm. A geometrical model is defined that considers the shape of the material filaments after deposition, to define a theoretical roughness profile, for a certain print orientation angle. Five different print orientations in the X-axis of the cuboid part were set: 0°, 30°, 45°, 60°, and 90°. According to previous research in the field of FDM technology by the author, the internal structure (infill) was set at the value of 70%. The method of 3D printing was the Fused Deposition Modeling (FDM) and the material used in this research was thermoplastic ABS (Acrylonitrile butadiene styrene). For each setting, there were five specimens (twenty five prints in total). Prints were fabricated on a Zortrax M200 3D printer. After the 3D printing, the surface “A” was investigated by portable surface roughness tester Mitutoyo SJ-210. Surface roughness in the article is shown in the form of graphs (Fig.7). Results show increase in part roughness with increasing degree of part orientation. When the direction of applied layers on the measured surface was horizontal, significant improvement in surface roughness was observed. Findings in this paper can be taken into consideration when designing parts, as they can contribute in achieving lower surface roughness values.

Numerical simulation of the melting of paraffin in the inclined straight channel shows that the melting speed of paraffin is faster in the early stage and gradually slows down in the later stage. It is found that heat conduction is the main heat transfer mode in the early stage of paraffin melting. With the increasing number of liquid paraffin, natural convection occurs in the liquid paraffin. The liquid paraffin with higher temperature flows upward due to the effect of buoyance and lift, and convection heat transfer gradually increases and takes the dominant position in the melting process.

An automobile company in this research faced the consistency problem from the chemical concentration in degreasing bath which was one of the stages in the pretreatment process. The problem came from the proportion of total alkaline (T.Al) lower than the lower control limit (LCL) which was set at 18.2 points during February – May 2020. This resulted in the low values of Cp and Cpk, i.e. 0.83 and 0.51, respectively. To remedy the problem, Six Sigma (DMAIC) was applied to improve the process stability. The cause and effect matrix was used to analyse the potential causes of problems and prioritise the causes to solve. It was found that four (causes) factors were solved by auto titration and feeding controller installation to reduce variance and increase stability. Another one factor, quality of water, was improved by adding a check item to monitor and collect data during the initial implementation stage. The result after improvement showed that Cp and Cpk were increased to 1.82 and 1.52 in August 2020, respectively.

The article proposes a method for obtaining a digital twin of the process of 3D printing by electric arc surfacing using an ensemble of machine learning methods. On the basis of the structural-parametric approach, a set of diagnostic parameters for the signals of current strength, voltage and acoustic emission was determined. Using exploratory analysis, the significance of each diagnostic parameter was assessed. A complex of statistical models has been developed to assess the stability of 3D printing processes using decision trees. Their optimal parameters and efficiency have been determined.

The scientific paper presents an extensive research on modeling and optimizing the technological parameters of the process for processing by processing electric discharges with massive electrode with and without magnetic activation. Scientific research is based on real data collected from the process of electrical discharges performed on various samples extracted from areas of welded joints of metal components made of high alloy steel. The processing of experimental data was performed both classically and actively, especially the method of the central factorial experiment composed of orthogonal and rotary. The process parameters that were initially modeled and subsequently optimized were based on a series of independent variables characteristic of dimensional processing by copying the shape of the electrical discharge processing. Subsequent research conclusions and directions, as well as original contributions, are an experimentally validated point of view and worthy of consideration. All these fundamental ideas highlighted above find their explanations and the corresponding explicit treatment in the content of this scientific paper that addresses both managers at all levels and researchers.

Replacing worn or damaged parts implies high material costs and financial expense for public tram transportation services, especially for the imported units and that is why it is preferable to recondition them, taking into consideration the safety requirements. In this paper, ISIM initiatives and achievements are presented in the field of cost reduction and maintenance during operation of trams, by introduction in the operation process of worn parts, within the safety limits. Aspects are presented regarding the possibilities for reconditioning and repair of parts with a circular geometry (e.g. wheel bands, axles, drum brakes). Some of these are being applied and implemented. Also, innovative ideas are presented for increasing the performance of equipment used for reconditioning.

The application of the 3D printing processes is continuously increasing due to their large number of technical and economic advantages when produce prototypes, but in the mass fabrication as well, especially for metal printing of low dimension products. The process produces pollution as all technological processes. Noise, fume and polymer wastes are the main elements which exit from the process and they are not products. The types and the volumes of those pollution emissions depend on the process parameters. The paper presents the results of FDM process emissions analysis. It was recorded the noise for different stages of the printer functioning. It was measured the volume and the contents of the fume produced during the extrusion of the polymer, for PLA polymer and for ABS polymer filaments. Specific risks were analysed and conclusions were reported. The measurement was done for a random chosen product and the results were compared with the pollutant emissions from traditional technological processes applied to erect the same type of product. It has been concluded that the noise emitted during the FDM printing is about 82-85% of the noise produced when apply milling to create similar shapes and dimensions (it was recorded values for the sound pressure in a large range: 42-68 dB, depending on the working regime). Regarding the fume emission, the intensity of emission was up to 40% higher in the FDM process comparing to the milling process. That was explained as being a direct result of the fluid-viscous state in which the material is put during the printing process. When discuss about the risks, most of the main identified risks in the milling and/or extrusion process were almost inexistent in the FDM printing. Electrical injuries and heat injuries are the main risks to which the operator is exposed. Mechanical injuries are sensitively lower than in the traditional processes, as milling The FDM process is safer and produces lower material wastes. It can be concluded that the FDM printing process has lower impact with the environment and with the operator.

The FSW process has proven to be a promising process for joining steels and improving their characteristics. However, the use of wrongs technological parameters leads to the appearance of defects. In this study, the macro and microstructural characteristics of steel joints and their mechanical properties are analyzed, and the main types of defects of the butt steel joints are presented. The main conclusions of the works studied are summarized and the main development directions for research on the characterization of steel structures joined by the FSW process are identified.

High-strength cable-steel bridge is the “lifeline” of steel structure bridges, which requires high comprehensive mechanical properties, and cold-drawing is the most important process to produce high-strength cable-steel bridge. Therefore, through the ABAQUS platform, a bridge wire drawing model was established, and the simulation analysis on the process of stress strain law and strain path trends for high-strength bridge steel wire from Φ 12.65 mm by seven cold-drawing to Φ 6.90 mm was conducted. The simulation results show that the wire drawing the heart of the main axial deformation, surface and sub-surface of the main axial and radial deformation occurred, with the increase in the number of drawing the road, the overall deformation of the wire was also more obvious non-uniformity. In the single-pass drawing process, the change in the potential relationship of each layer of material was small, and multiple inflection points appeared in the strain path diagram; the change in the seven-pass potential relationship was more drastic, which can basically be regarded as a simple superposition of multiple single-pass pulls.

Finite Element Method (FEM) becomes one of the most useful techniques to analyze problems in sheet metal forming processes because of this technique can reduce cost and time in die design and trial step [1]. This research was aimed to predict the optimal parameters in order to eliminate cracks and wrinkles on stainless steel sink product under deep drawing named “DLS50”. The material was made from Stainless Steel 304 with thickness 0.6 mm. The parameters that had been investigated were punch angle and velocity as well as pressure of the punch. In order to simplify the process, punch and die in the simulation were assumed to be a rigid body, which neglected the small effect of elastic deformation. The properties of stainless steel sheet was assumed to be anisotropic, behaved according to constitutive equation of power law and deformed elastic-viscoplastic, which followed Barlat 3 components yield function. The deformation for Forming Limit Diagram (FLD) was predicted by the Keeler equation. Most of the defects such as cracks and wrinkles were found during the process on the parts. In the past, practical productions were performed by trial and error, which involved high production cost, long lead time, and wasted materials. From the prediction results, decreasing punch velocity from 50 mm/s to 8.33 mm/s would reduce the blank shearing zone on the corner bottom of the part and remove cracks in the process. The performing of the stainless sink by decreasing pressure in the process from 2.3 bar to 2 bar, and adjusting the punch shape increasing 5 mm. each side would increase formability of sheet metal in all direction, the reduction of cracking tendency zone out of the part. In conclusion by using the simulation technique, the production quality and performance had been improved.

Modeling the processes of forming contact regions (interface) of the multilayer niobium-cobalt nanosystem is carried out. The morphology and composition of a multilayer nanosystem interface is investigated. The layer boundaries morphology is shown to depend on the deposition substrate temperature and, largely, is determined by preparing the surface for deposition. The work considers the deposition surface modification by removing its defects. Simulation showed that surface preparation significantly affects the morphology and composition of a multilayer nanosystem interface, depending on the type of deposited atoms and atoms forming the deposition surface.

Single point incremental forming (SPIF) is a choice of interest in many manufacturing industries due to its wide range of applications. Materials such as copper, aluminum, steel, and many others formed various complex shapes through this process. However, the forming process could sometimes result in process defects, which could strongly influence the formed parts' geometric accuracy. The twist defect is one of them, which incrementally twists the forming sheet with a small angle at each forming step. In this paper, twist phenomena in the SPIF process have been investigated both numerically and experimentally. In the experiment, Aluminum Alloy (AA5052) was used to form a truncated pyramid shape, and a room temperature tensile test has been conducted to achieve the material's tensile properties. Then, the material property used in the simulation study of the SPIF using LS-DYNA software, where twist defect, stresses, strain, and thickness distribution are studied. The results from simulation and experiment show significant similarity against the expected results and this conveys that the proposed FE model of the SPIF process can be used to investigate the presence of twist, distributions of stress and strain, and thinning locations in the formed part.

Mechanical properties of extruded aluminum are known to significantly depend on the process parameters such as temperature, numbers of extrusion pass and extrusion load among others. This implies that these properties can be influenced by tuning the process parameters. Herein, the effects of these parameters on the tensile strength and hardness of aluminum 6063 series were investigated by using equal channel angular extrusion (ECAE). Experiments were designed using Design Expert software. Analysis of variance (ANOVA) was then used to investigate the main and interactions effects of the process parameters. An empirical mathematical model was generated that shows the relationship between the input and output variables using response surface methodology. Temperature was found to be the most significant factor while extrusion load was the least factor that influenced the hardness and tensile strength which were the output factors. There was a significant increase in tensile strength and hardness after extrusion at different mix of factors. The optimum input variable was discovered at 1020.58 kN, 489.67°C and 3 numbers of extrusion passes.

The article presents the technological scheme of the “stretching-over” hybrid technology, when the workpiece is simultaneously affected by two sources of loading: static and dynamic. It is proposed to use a pulsed magnetic field as a dynamic load. In this case, the tightening punch is equipped with an inductor connected to a magnetic-pulse unit. As a result of computer simulation, the distribution patterns of the stress-strain state in a tight-fitting workpiece were obtained both in the case of a conventional tight-fitting and with the proposed hybrid one. It was found that exposure to a pulsed magnetic field changes the stress-strain state, making it possible to intensify the stretching process.

Analytical and experimental studies have been carried out, which made it possible to propose new technological modes of combined rolling-extruding for the production of rods from alloy 01417 for the further drawing of wire for electrical purposes. The force parameters on the rolls and the die are calculated when extruding a rod with a diameter of 5 mm on the laboratory unit CRE-200 and the industrial unit CRE-400. The obtained values of the forces on the rolls and the die do not exceed the permissible values of the power load of the units. Therefore the selected parameters are suitable for conducting experiments on the manufacture of prototypes of rods. To verify the conclusions made, experimental studies were carried out on the CRE-200 unit at a temperature of 320 oC and a drawing coefficient μ = 12.1. The results of experimental studies in comparison with the calculated data showed that the deviation of the calculated data does not exceed 15%.

Despite years of supporting research, commercial use of the Single Point Incremental Forming process remains very limited. The promised flexibility and lack of specific tooling is contradicted by its highly complex deformation mechanics, resulting in a process that is easy to implement but where workpiece accuracy is very difficult to control. This paper looks at geometry compensation as a viable control strategy to increase the accuracy of produced workpieces. The input geometry of the process can be compensated using knowledge about the deformations occurring during production. The deviations between the nominal CAD geometry and the actual produced geometry can be calculated in a variety of different ways, thus directly influencing the compensation. Two different alignment methods and three deviation calculation methods are explained in detail. Six combined deviation calculation methods are used to generate compensated inputs, which are experimentally produced and compared to the uncompensated part. All different methods are able to noticeably improve the accuracy, with the production alignment and closest point deviation calculation achieving the best results

The paper analyzes the influence of tension (dam) on the technological parameters of the rolling process (spreading, force and rolling torque). For the analysis, a model of continuous rolling in three adjacent stands was developed, using the Deform 3D software. The adequacy of the model was confirmed by comparing the experimental data from the small-section wire mill 150 and the simulation results. The error in determining the forming was 0.4%, and in determining the power parameters was 11%. Further, a computational experiment was planned, to identify the effect of mismatched of rolling speeds on technological parameters. According to the results of calculations, graphs of changes in technological parameters were constructed. It is established that, even small deviations of rolling speed from the matched mode lead to significant changes in technological parameters.

Manufacturing processes have a significant impact on global energy consumptions. The recovery of materials and functions for the implementation of the Circular Economy principle needs to be focused on either, by utilizing new techniques or the rethinking of old processes to rework End-of-life (EoL) components. Previous researches have shown Single Point Incremental Forming (SPIF) process as a good alternate for sheet metal EoL components reuse by their reshaping. In this article, the authors aim to study the effectiveness of the SIPF processes by comparing its reshaping performance with other, more conventional forming processes. An initial deep drawing process was performed to imitate aluminum sheet metal EoL component, subsequently, different stretching-based reshaping approaches have been tested. Results revealed that SPIF outperformed conventional forming processes, as proved to be the only approach leading to new/reshaped component

Mechanized arc welding is divided into two main varieties: with self-regulation of the electrode melting process and with automatic process control. The common thing between self-regulating mechanized arc welding and manual arc welding is that in the welding equipment there are no means for automatic control with feedback from the arc. The difference between them is that stabilization of the electrode melting process in mechanized welding is carried out by the source itself, which has a particular volt-ampere characteristic (CVC), by a corresponding spontaneous reaction to a change in the situation in the arc. This method is significantly inferior to the method with automatic process control in precisely maintaining the specified parameters and has a limitation on the minimum current density on the electrode. The method of pulse self-regulation of the electrode melting process proposed in the E.O.Paton EWI removes this problem. However, it requires the use of power sources with a complicated, multi-link CVC curve. Further improvement is revealed through the use of digital controlled, programmable power supplies that have an automatically generated CVC. The combination of automatic source control and self-regulation by the spontaneous reaction to the situation in the arc creates a new hybrid way to stabilize the process of arc welding with a consumable electrode and other related arc processes (surfacing, soldering, re-melting).

Pipe steel sheet is manufactured by hot rolling technological process. Technological regimes of every technological operation can vary in a wide range affecting pipe steel sheet properties. It is shown that system analysis provides the effective way for searching out the basics for mathematical modeling of multi-variant technological processes. The detailed scheme of steel sheet hot rolling process is presented, determining its input and output parameters. Flows of material, energy, and information are presented for each technological operation. Metallurgical concept of pipe steel manufacturing is shown as the basics for competitive product manufacturing. It is proposed to analyze the hot rolling process as a set of target functions, which will make it possible to achieve the pipe steel sheet with the desired level of mechanical properties. The proposed approach based on system analysis allows to find tendencies for further development of hot rolling.

Joining and local forming processes for fibre-reinforced thermoplastics (FRTP) like hole-forming or variations of the clinching process require an in-depth understanding of the process induced effects on meso-scale. For numerical modelling with a geometrical description of a woven fabric, adequate material models for a representative unit cell are identified. Model calibration is achieved employing a mesoscopic finite-element-approach using the embedded element method based on tensile tests of the consolidated organo-sheets and a phenomenological evaluation of photomicrographs. The model takes temperature dependent stiffness and fibre tension failure into account.

Due to increasing demands regarding ecological and economic specifications in vehicle design, the effort required for production is continuously increasing. One trend is the increased use of multi-material systems, which are characterised by the use of different materials such as high-strength steels or aluminium alloys. In addition to the varying mechanical properties of the components, an increased number of variants accompanied by different geometries is leading to increasing challenges on body construction. For the assembly and connection of the individual components, conventional joining methods reach their limitations. Therefore, new joining methods are necessary, which feature properties of versatility and can adapt to process and disturbance variables. One way of achieving tailored joints is to use a tumbling self-piercing riveting process. For the design of the process route, numerical investigations are necessary for which a characterisation of the friction properties is necessary. This paper therefore investigates the contact and friction conditions that occur in a tumbling self-piercing riveting process. The individual contacts between the process components are identified and based on this, suitable processes for the characterisation of the friction factors - and coefficients are selected and performed.

The increasing need for prosthetic hands for people with disabilities is one reason for innovation in the field of prosthetic hands to create the best prosthetic hand technology. In the design of EMG-based prosthetic hands, this is determined by several things, among others, the selection of features. The selection of the right features will determine the accuracy of the prosthetic hand Therefore, the purpose of this study is to analysis the time domain feature to obtain the best feature in classifying the hand motion. The contribution of this work is able to detect 4 movements in real time, namely hand close, flexion, extension, and relax. The Electromyograph signal is tapped using an electromyograph (EMG) dry electrode sensor in which there is a circuit of EMG instrumentation amplifier. Furthermore, the analog EMG signal data is processed through the ADC (Analog to Digital Converter) by using MCP3008 device. EMG signal data is processed in Raspberry Pi. A feature extraction process is applied to reduce data and determine the characteristics of each hand movement. Feature extraction used is MAV (mean absolute value), SSI (sign slope integral), VAR (variance), and RMS (root mean square). From the results of the four-time domain feature, then the best feature extraction is determined using scatter plot and Euclidean distance. The results that have been carried out on ten people with each person doing ten sets of movements (hand close, flexion, extension, relax), showing the best Euclidean distance results, is the RMS feature, with a value of 2608.07. This data is the result of the best feature extraction analysis through the method of calculating the distance of feature extraction data using Euclidean distance. This analysis of time domain feature is expected to be useful for further experiment in machine learning implementation so that it can be obtained an effective prosthetic hand.

Torrefaction process is the innovation to improve the properties of biomass. Residence time is one of the parameters that affects the properties of torrefied biomass. The residence time of a rotary kiln is the time of biomass drop into the cylinder until getting out of the cylinder. So, the propose of this study is the effect of lifters, inclination angle and rotational speed on the residence time of a rotary kiln for the torrefaction process. Palm kernel shell was used in this research. Palm kernel was chopped and minced to reduce size. The rotary kiln (0.3 meters diameter 6 meters in length) was used in this research. The number of lifters in this research were 0, 1 and 2. The rotational speed were 1, 2 and 3 rpm. The inclination angle was 1, 3 and 5 degrees. The hopper was used for the feeding system. The time was collected from biomass drop into the cylinder until getting out of the cylinder. The results reveal that the number of lifters, rotational speed and inclination angle affects the residence time of the rotary kiln. The residence time of rotary kiln was an increase when the number of lifters increase. The residence time of the rotary kiln was decreased when the rotational speed and inclination angle increase. It can be concluded that the least residence time of rotary kiln was 86.94 minute at 0 lifters, 3 rpm and 5 degrees. The most residence time was 9.22 minute at 2 lifters, 1 rpm and 1 degree.

Because of the general problem of the welding workpiece such as fatigue fracture caused by tensile residual stress lead to initial and propagation crack in the fusion zone. Thus, the mechanical surface treatment of deep rolling on Gas Tungsten Arc Welded (GTAW) surfaces of AISI 316L was studied. Deep rolling (DR) is a cold working process to induce compressive residual stress in the surface layer of the workpiece resulting in hardening deformation which increased surface hardness, and smooth surface that inhibit crack growth and improve fracture strength of materials. The present study focuses on compressive residual stress at the surface of stainless steel AISI 316L butt welded joint of GTAW. The three parameters of DR process were used; pressure 150 bar, rolling speed 400 mm/min, and step over 1.0 mm. The residual stresses analysis by X-ray diffraction with sin2Ψ method at 0, 5, 10, and 20 mm from the center of the welded bead. The results showed that the DR process on the welded of GTAW induce the minimum compressive residual stress-408.6 MPa and maximum-498.1 MPa in longitudinal direction. The results of transverse residual stress in minimum and maximum are 43.7 MPa and-34.8 MPa respectively. The FWHM of DR both longitudinal and transverse direction were increased in the same trend. Furthermore, the microhardness after DR treatment on workpiece surface layer higher than GTAW average 0.4 times.

Stirring tool is one of the important factor that contribute to the successful of Friction Stir Welding (FSW). Role of tool, is to heat the welding zone and stir the material along the process. Many studies have been conducted by other researchers to improve the performance of stirring tool. Similar to this work, it is aimed to investigate and analyze the effect of stirring tool surface condition on wear characteristics in friction stir welding process. Four tools have been fabricated with pre-determined surface condition. Tool 1: H13 without heat treatment and without coating. Tool 2: H13 with heat treatment only. Tool 3: H13 with TiCN coating only and Tool 4: H13 with heat treatment and with TiCN coating. Friction stir welding was performed to test and verify the performance of fabricated tools. Process parameter used are 1270 RPM for rotating speed while 218 mm/min for welding speed. From the result, Tool 4 performed better in terms of physical wear as well as wear rate.

In this paper, the microstructure evolution during continuous hot rolling process of GCr15 steel rod was investigated. A series of multi-field coupled finite element models were established based on commercial finite element software MSC.Marc. The kinetics equations of austenite grain size evolution of GCr15 steel were coupled to these models by a designed MSC.Marc subprogram. The field variables, including temperature, equivalent stress, equivalent strain, and equivalent strain rate, were calculated. The distributions of dynamic recrystallization, metadynamic recrystallization, and static recrystallization fractions were investigated. The distribution and evolution of austenite grain size at different stages in the continuous hot rolling process were analyzed. To verify the models, the temperatures of GCr15 steel rod at different stages in the continuous hot rolling process were measured. And the austenite grain sizes at cross section of the rod after the continuous hot rolling process were measured. The simulation results show a good agreement with the experimental results.

Electrohydraulic forming (EHF) is a kind of high speed forming process, which deforms the metal by shock wave through instantaneous discharge of high voltage in water. Compared with the traditional forming methods, this high speed forming process can greatly improve the formability of the materials. There are many processing factors that affect the forming efficiency and performance of the electrohydraulic forming process, one of which is the discharge voltage between the electrodes. In this paper, three electrohydraulic forming experiments with various die shapes were carried out under various discharge voltage conditions. And the bulge height and axial length of the aluminum alloy A6061 tubes under different conditions were compared. Besides, finite element numerical simulation was also performed to quantitatively investigate the deformation history of the tube.

The reported paper presents a field pattern of sliding lines in a plastic zone of flow chip formation in the process of cutting metals considered for front and rear angles on the cutting blade other than zero. Equations of sliding lines for these conditions are proposed. Using calculation data, plasticity zone border lines are plotted for positive and negative front angles. The paper suggests methods and calculation data on average stress and plane stress state components in nodal points of the plastic zone of chip formation. The study provides data for plotting distribution diagrams of normal and tangential stresses of contact stresses on work surfaces of a cutting blade.

To further improve the finishing efficiency, it has been proposed to apply full-wave rectified current to the coil. In this paper, the effect of full-wave rectified current on the magnetic field and finishing force is studied. The effects of full-wave rectified current and alternating current on finishing characteristics were compared through experiments. The experimental results show that, with different magnetic particle sizes, the finishing efficiency shows different results. In the case of full-wave rectified current, when the average diameter of the magnetic particles is 30 μm, 75 μm and 149 μm, the finishing efficiency is higher than the alternating current, and when the average diameter of the magnetic particles is 330 μm, the finishing efficiency is lower than the alternating current.

This paper aims to find the impact of Electric Discharge Machining (EDM) factors on material removal rate (MRR) for 90CrSi alloy steel. Five three-level factors including pulse on time (Ton), pulse off time (Toff), pulse current (IP), server voltage (SV), and diameter of work-piece (dw) are investigated to explore their contribution on MRR by using Taguchi method in twenty-seven experiments based on an orthogonal array L27 (35). The findings realize that MRR is the most affected by the pulse current while the effect of the dw is the smallest. Based on ANOVA analysis, an optimal model of MRR has been developed and verified by comparing with the experiment result. The applicability of this proposed method can be used for further studies in EDM process.

The traditional magnetic abrasive finishing (MAF) process, the magnetic flux density at the bottom of the magnetic pole is unevenly distributed, resulting in poor uniformity of the finished surface. Therefore, it is proposed to improve the surface quality by attaching a magnetic plate at the bottom of the workpiece to improve the magnetic field distribution. It is confirmed by simulation that the magnetic field distribution at the bottom of the magnetic pole is effectively improved after the magnetic plate is attached. It is proved through experiments that the magnetic plate-assisted MAF process can obtain a smoother surface. The experimental results show that the surface roughness of the glass lens improves from 246 nm Ra to 3 nm Ra through the magnetic plate-assisted MAF process within 45min.

This study focuses on the multi-objective optimization of the welding joint of AISI 1045 steel shafts with AISI 1070 filler wire 1.8 mm in diameter by electric resistance welding method. During the welding process, welding parameters input are important because it determines the quality of the welding joint. Therefore, in this study, Taguchi method was used in combination with grey relational analysis to select the welding parameters suitable for this welding process. The experiments were performed according to the orthogonal array L9 designed by the Taguchi method. The input welding mode parameters used in this study include welding current (Ih), force (F), welding speed (Vh). The output characteristics for the selected weld quality target are minimum tensile strength and micro hardness. Grey analyzes were conducted to optimize for the input parameters, the analysis results show that the set of input parameters suitable for the output quality are Ih = 7.5 KA; F = 1.7 KN; Vh = 1.5 cm/s. This is followed by the process of assessing the significance of the factors to all qualities of the welded joint using the ANOVA analysis process.

The adaptive control of metal cutting processes is a logical extension of the CNC systems. In CNC systems of metal-cutting processes the machining variables (e.g., the cutting speed and feedrate) are prescribed by the part programmer. The determination of these variables depends on experience and knowledge regarding the workpiece and tool materials, coolant conditions, and other factors.The determination of these operating parameters depends on experience and knowledgeregarding the workpiece and tool materials, coolant conditions, and other factors. By contrast,the main idea in adaptive control is the improvement of the production rate, or the reductionof machining costs, by calculation and setting of the optimal operating parameters duringmachining itself. This calculation is based upon measurements of process variables in real time and is followed by a subsequent on-line adjustment of the machining variables subject to constraints with the objective to optimize the performance of the overall system.The adaptive control is basically a feedback system, in which the operatingparameters automatically adapt themselves to actual condition of the process. AC system formachine tools can be classified into two categories:1.Adaptive control with optimization(ACO);2.Adaptive control with constraints(ACC);ACO refers to systems in which a given performance index (usually an economicfunction) is extremized subject to process and system constraints. With ACC, the machiningparameters are maximized within a prescribed region bounded by process and systemconstraints, such as maximum torque or power. ACC systems, however, do not use aperformance index. In both systems an adaptation strategy is used to vary the operatingparameters in real time cutting progresses. Although there has been considerable research onthe development of ACO systems, few, if any, of these systems are used in practice. The major problems with such systems have been difficulties in defining realistic indexes of performance and the lack of suitable sensors which can reliably measure on-line thenecessary parameters in a production environment. The objective of most AC systems isimprovement in productivity, which is achieved by increasing the metal removal rate (MRR)during rough cutting operations. The increases in productivity range from approximately 20 to 80 percent and clearly depend on the material being machined and the complexity of the part tobe produced.

In this paper, non-isothermal analysis of an automatic multi-stage cold forging process of a ball-stud is conducted using a new material model which is a closed form function of strain, temperature and strain rate covering low and warm temperatures for high-strength stainless steel SUS304. An assembled die structural analysis scheme is employed for revealing the detailed die stresses, which is of great importance for process and die design for metal forming of the materials with high strengths. Die elastic deformation is dealt with to predict final geometries of material with higher accuracy. A complete analysis model is proposed to be used for optimal design of process and die designs in automatic multi-stage cold forging of high-strength materials.

The orthogonal experiment method is used in optimal design of laser cladding, such as laser power (P), scanning speed (SS), powder feeding rate (PFR) and shielding gas velocity (SGV) etc. Both the dilution rate and the aspect ratio are investigated by comprehensive scoring method, which transforms multi-index into single index. In view of the nonlinear characteristics of laser cladding process parameters, the optimum level of each factor based on interaction effect is obtained by analyzing binary tables. Finally, the relationship between the laser cladding process parameters and the two indexes (the dilution rate and the ratio of width to height of coating) is obtained. This method has potential applications for the further investigating on the laser cladding process rules.

In deep hole machining, drilling parameters for twist drills have an important impact on tool life and economic efficiency. In order to explore the influence of drilling parameters on twist drills, this paper established a drilling model for twist drill 45 steel, orthogonal experiments were designed. AdvantEdge FEM finite element software was used to simulate the drilling force, torque and drilling temperature. The drilling force, torque and drilling temperature were analyzed by using the finite element simulation value as the orthogonal experimental value. In order to ensure that the simulation results have certain reference value, the drilling experiment was carried out in order to ensure the simulation results have reference value. Finally, the optimal combination of drilling parameters was obtained.

This study aims to plan the no-tail, i.e. zero waste, automatic cold forging model through the innovative development of a die to directly produce finished nail tails without second processing. It could enhance production efficiency, reduce production costs, and conform to the new model of zero waste under “circular economy”.

Reaming is one of the finishing processes that has been widely applied in automotive industry. Reaming parameters were evaluated and optimized based on multiple performance characteristics including tool wear and hole quality. Taguchi’s L16, 4-level, 2-factor orthogonal array (OA) was conducted for this test. It was shown that crater wear and flank wear were seen on the tool surface. Furthermore, the crater wear was also of major significance. Hole quality was discovered to be mostly dependent upon cutting speed and feed rate. TiAlN coated carbide reamer shows the best performance with respect to the tool wear as well as hole quality. Grey relational analysis used as a multiple-response optimization technique found that feed rate was the more influential parameter than cutting speed. The goal of the experimental results was to obtain both minimum diametral error and the value of surface roughness by adopting the optimal combination of the reaming parameters.

In this paper, the effect of abrasive water jet cutting process on the surface character of medical implant SS316L was investigated. This research focuses on the effect of traverse speed during abrasive water jet cutting on the surface roughness and topography of medical implant material SS316L. In some study, it has been noted that the roughness of implant material correlates with the healing process of a sufferer in medical application. Furthermore, transverse speed has an important role in the manufacturing process that correlates directly with the ability of technic to produce a product at a definite time. Garnet was used as an abrasive material in this water jet cutting process. The process was taking place in room temperature with 3000Psi of water pressure. In this study, the surface roughness was examined at all point of depth of the cut surface in all of the transverse speed using Mitutoyo SJ 210, while the surface topography observed by Olympus BX53M optical microscope. The study results reveal that traverse speed has a significant effect on the surface roughness at the surface, middle, and bottom of the cut point. The Surface roughness increase as transverse speed.

The results of computer simulation of the process of combined rolling-extruding of longish deformed semi-finished products from alloy 01417 are presented. A feature of the research is that continuously cast bars with a diameter of 12.5 mm obtained using an electromagnetic mold are used as a workpiece. This makes it possible to increase the manufacturability of processing and to obtain after rolling-extruding billets for drawing with a diameter of 5 mm with a large resource of plastic and strength properties. For this case the technological parameters and temperature and speed conditions of combined processing have not yet been studied, therefore, their analysis was performed using the Deform-3D software package. It has been revealed that the feasibility of the rolling-extruding process is significantly affected by the frequency of rotation of the rolls. Moreover, the process becomes unstable when the value of this parameter is 4 rpm, which can be explained by insufficient degrees of deformation during rolling, and consequently by the small value of the active friction forces acting on the contact surface of the metal with the rolls. As a result of this, the processing temperature conditions also change, which is also demonstrated using the developed computer model. As a result, it was found that for the stable course of the combined rolling-extruding process at the CRE-200 unit of a continuously cast billet with a diameter of 12.5 mm from alloy 01417 at a heating temperature of the billet of 550 °C and a tool of 200 °C, degree of deformation during rolling 44% and drawing ratio during extruding 18.6 the frequency of rotation of the rolls should be at least 8 rpm. The simulation data used during the implementation of the process at the combined processing unit CRE-200, the results of which made it possible to finally obtain electrotechnical wire with a diameter of 0.5 mm from 01417 alloy that meets the requirements of TS 1-809-63-2018.

Nickel-base superalloys are used as a land-base turbine engine due to its excellent properties at elevated temperatures. Nickel base superalloy, grade IN-738. Laser welding is commonly chosen for the refurbishment of the turbine blade. This paper aims to focus on understanding welding speed parameters in laser welding method. With constant power at 400 watts, welding speeds were varied from 1, 3, 5, and 8 mm/s. All of these alloys have no cracks found in fusion zone, HAZ, and bulk area. Increasing welding speed results in less heat energy input, reduces the penetration depth and weld pool area. The 1mm/s, which were subjected to the highest heat energy input, results in very small size of the γ’ precipitates in the fusion zone due to re-precipitation of the γ’ precipitates during the solidification process. The fusion zone also exhibits the highest hardness. The size of the γ’ precipitates in HAZ area are much larger, compared to the fusion zone The bulk areas have no effect from the heat and showed much larger size of the γ’ precipitates, which was caused by microstructural degradation during service, leads to the lowest hardness value among the three zones.

Understanding and predicting relationships between laser welding process parameters, such as laser power and welding speed, and molten pool have been studied widely in order to critically control and improve laser welding. The laser welding processes are difficult to monitor in real time because of high temperature and rapid heating characteristics. In this study, infrared camera was set to collect data and provide real time monitoring system to determine the molten pool characteristics and weld quality. This study carried out a laser welding of SS400 low carbon steel and analyzed real-time image of the welding process to determine the average temperature of molten pool and calculate the size of molten pool. By varying the laser power and the welding speed, the infrared camera and imaging processing technique can monitor change of molten pool temperature in a range of 1000 C to 15000 C with about 1% temperature fluctuation. In addition, the size of molten pool can be calculated from the temperature profile of the welding zone. The calculated molten pool size was about 95% accurate compared to the measured size from microscope imaging.

Nowadays, the industry has been growing interest in lightweight material for automotive and cookware manufacturing. The formability of sheet material is an important issue in these industries. The wrinkling behavior is one of the most failure in sheet metal forming and is often occurred in deep drawing process in cookware manufacturing. In this work, the developed wrinkling limit curves (WLCs) using experimental and numerical simulation of a modified Yoshida buckling test were precisely used to predict the wrinkling behavior of rectangular cup deep drawing for aluminum alloy sheets grade AA5054-O and AA5052-H32. The Industrial parts, the rectangular cup deep drawing was firstly performed for both investigated aluminum sheets for obtaining the wrinkling initiation on the side wall area of deep drawing parts. Subsequently, the experimental formed parts were carefully measured the draw-in of deformed blank sheets and drawing depth to validate the finite element (FE) model. Then, the FE simulation of the corresponding drawing tests were calculated, by which were implemented with the Hill’48 yield criterion and Swift hardening law to descript anisotropic plastic deformation. As a result, the local principle Major and Minor principle strains of observed wrinkle areas were gathered in the side wall area of the rectangular cup deep drawing test. Finally, the developed WLCs of aluminum alloy sheets were applied to predict the wrinkling formation of the formed deep drawing parts. Comparatively, the influence of different aluminum alloy grades on the WLCs and wrinkling behavior were explicitly investigated.