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Results 91 to 120 of 294:

Strain Field Determination for Additively Manufactured Thermoplastics Using Computer Vision

Jaroslav Majko, Ondrej Piroh, Ján Minárik, Milan Vaško, Marián Handrik, Milan Sága, Zbigniew Saternus

Manufacturing Technology 2025, 25(4):511-520 | DOI: 10.21062/mft.2025.060

The effective application of additively manufactured materials requires accurate identification of their mechanical properties as well as damage mechanisms. Computer vision offers a novel approach for non-contact measurements, enabling the identification of selected mechanical properties. This paper presents a new method based on image analysis and the detection of circular markers for non-contact displacement measurements. The core principle involves detecting the centers of gravity of the circular markers formed on the sample under investigation. The centers of gravity are evaluated on each image created during the tensile test, representing nodal points. At these points, displacements are determined based on the non-contact extensometer. The deformations sought are a function of the displacements at each nodal point. These values were calculated based on several theoretical models, also used in the finite element analysis. The paper describes the computational procedure for determining the deformations based on the mentioned theoretical models. Subsequently, the total strain field is determined using linear interpolation of the displacement values at the individual nodal points. The results provided by each of the theoretical models were compared.

Possibility of Eliminating Iron in Aluminium Alloy Through Sedimentation

Štefan Michna, Anna Knaislová, Jaroslava Svobodová, Jan Novotný, Lenka Michnová

Manufacturing Technology 2024, 24(5):802-810 | DOI: 10.21062/mft.2024.082

The article is dedicated to research on the elimination of high iron content (above 3-4%) in aluminium alloys through sedimentation. The aim was to determine the effect of sedimentation time on reducing the iron content in material from a refining bath with high iron content and to identify the phases formed in the structure. Melts were prepared from the material obtained from the refining bath, which consisted of an AlSi12 alloy with 3-4% Fe content. After melting, sedimentation was carried out for 2 hours, 4 hours, and 6 hours. Sedimentation was conducted while maintaining the alloy in a liquid state throughout the entire sedimentation period. After sedimentation and cooling of the castings, samples were taken to prepare metallographic specimens, and analyses were conducted to measure the iron content in the individual samples and to observe the reduction of iron content depending on the sedimentation time. Additionally, the identification and description of the intermetallic phases formed in the structures of the sedimenting castings from the refining bath were carried out using a scanning electron microscope with EDS analysis.

Parameter Optimization Study of Ultra-High Speed Cutting by DOE Method

Dongya Li, Yichen Jiang, Shuang Wang, Yifan Wu

Manufacturing Technology 2024, 24(1):73-82 | DOI: 10.21062/mft.2024.004

With the increasing demand for high-quality flange, there is a greater need for high-quality and high-speed machining technology. Aiming at the difficulty of surface roughness in meeting design requirements and poor machining stability of 7075 aluminum alloy, the classical Design of Experiments (DOE) method is employed to optimize the machining parameters and identify eight pertinent factors. By selecting the feed rate and cutting speed as the two significant factors, a  mathematical model of roughness is derived, and the theoretically optimal machining parameters are determined. According to corresponding experimental results, the roughness, the parallelism of the two end faces of the flange, and machining efficiency, in order to further validate the accuracy of the model. The final processing parameters are 0.07 mm.r-1 feed rate and 1100 m.min-1 cutting speed, which provide a reference for actual production.

Identification of Machine Tool Defects Using Laser Interferometer

Miroslav Matuš, Vladimír Bechný, Richard Joch, Mário Drbúl, Andrej Czán, Michal Šajgalík

Manufacturing Technology 2024, 24(3):420-428 | DOI: 10.21062/mft.2024.052

The geometric accuracy of a machine is primarily determined by the accuracy of assembly, manufactur-ing, and overall setup. Standardized procedures for assessing geometric accuracy are established and detailed in delivery protocols for various types of machining machines. To effectively monitor and ana-lyze machining machine errors, the most suitable approach is to construct a comprehensive error balance that accounts for the overall performance of the machine. This error balance methodology, a tool within the realm of system analysis, is utilized for predicting and managing systemic errors. The errors ob-served in machined components are intimately connected to the errors present in the machining ma-chines themselves. These errors are further intertwined with the design and physical properties of indi-vidual machine components, as well as their interactions. In the case of multi-axis machines, they col-lectively determine the overall accuracy of the produced components. The objective of this study is to analyze machining machine errors using the Renishaw XL-80 laser interferometric system. The findings of this study reveal that errors in machining machines can also be the result of the dynamics of the cut-ting process, which may have a significant impact on accuracy.

Quantification and Verification of Swingarm Structural characteristics through Numerical Simulation and Photogrammetry

Lukas Gregor, Jan Zouhar, Radim Kupcak

Manufacturing Technology 2024, 24(5):765-778 | DOI: 10.21062/mft.2024.085

Composite materials have consistently been applied in areas where a combination of properties such as strength, stiffness, and low weight is crucial. Motorcycle construction is no exception, as these parameters significantly impact riding characteristics, safety, and overall performance. This article focuses on quantifying the torsional and vertical stiffness of a single-sided swingarm made of carbon fiber reinforced polymer (CFRP) using finite element analysis (FEA) and verifying these results through experimental measurements. To enhance the accuracy of the simulations, which involve complex geometries and anisotropic materials, the material properties of selected fabrics used in the prototype production were measured. Specific fixtures were designed for the experimental measurements, enabling the application of torsional moments and vertical forces. Deformation under these loads was evaluated using the TRITOP photogrammetric system, which tracks deformations by monitoring the displacement of reference points under static load conditions and comparing them to a reference, unloaded state. Based on the acquired data, the overall stiffness values and their distribution along the length of the swingarm were calculated. The results showed a significant difference between simulation and reality. For the overall torsional stiffness, the simulated value was 249 N·m/°, while the measured was 270 N·m/°, showing a discrepancy of 7.7%. The vertical stiffness value from simulation was 414 N/mm, compared to 411 N/mm from experimental measurements, with a minimal difference of -0.7%. The stiffness distribution along the length of the swingarm exhibited a correlation, but with notable variation in certain areas. This confirms that accurately simulating CFRP parts with complex geometries is highly challenging, partly due to the sensitivity of the manufacturing process. Therefore, verification through experimental measurement is considered good practice.

Enhancing Durability of Multi-Cavity Forging Tools through Process Automation

Artur Meller, Stanisław Legutko, Adrian Mróz, Mariusz Piechowski, Hubert Kędziora, Vit Cernohlavek

Manufacturing Technology 2024, 24(6):929-939 | DOI: 10.21062/mft.2024.105

The article highlights the promising potential of automating the forging process to enhance the durability of multi-cavity forging tools. Entrepreneurs aim to boost production efficiency by increasing output per unit of time and reducing the degradation of forging dies and punches. The high costs associated with specialized materials and complex manufacturing processes for these tools elevate the final product price. Automation offers a viable alternative, ensuring consistent process parameters and reducing the physical strain on workers. This consistency leads to extended tool durability, even without the use of special manufacturing techniques for their production. The study simulates the durability of multi-cavity dies in automated operations, demonstrating substantial advantages compared to manual forging. Simulation programs for forging processes and tool durability offer significant cost savings by providing insights into potential fatigue cracks, aiding in decision-making, and verifying operational parameters and tool designs. These simulations reduce the need for extensive: real-world tests and modifications of the forging tools.

The Effect of the Solution Annealing Temperature in the Hardening Process on the Properties of Al-Si-Cu Alloys

Tomáš Vlach, Jaromír Cais, Filip Mamoń, Jakub Mareš

Manufacturing Technology 2024, 24(1):141-147 | DOI: 10.21062/mft.2024.011

This article deals with the influence of the applied solution annealing temperatures in the precipita-tion hardening process on the resulting increase in the mechanical properties of Al-Si-Cu alloy cast-ings with different copper contents in the alloy. AlSi7Cu2 and AlSi7Cu4 alloys were cast by gravity casting in a metal molds. Each of the samples was subjected to the Vickers microhardness measure-ment of a solid solution of α(Al) and Brinnel hardness measurement. Microscopic analysis and evalu-ation of the internal structure of each alloy was carried out in relation to used solution-annealing temperature.

Carbide Twist Drill Spiral Groove Abrasive Flow Polishing and Abrasive Flow Analysis

Tian Ji, Lintao Lu, Boming Ren, Guihong Bian, Shengli Huang

Manufacturing Technology 2024, 24(2):197-206

This paper carries out the simulation of abrasive flow for twist drill spiral grooves and the experimental study of abrasive flow polishing. The flow of abrasive in spiral groove in abrasive flow polishing twist drill was analyzed by CFD using FLUENT software. Different inlet speeds and abrasive concentrations were used as parameters for simulation calculations to obtain the state parameters of dynamic pressure and abrasive velocity in the flow channel, and to analyse their effects on the abrasive flow in the spiral groove. The analysis results show that the dynamic pressure in the twist drill spiral groove increases with the increase of inlet speed, and becomes smaller as the abrasive flows along the spiral surface. Under the condition of different abrasive concentrations, the velocity of abrasive decreases with the increase of abrasive concentration. Under the same abrasive concentration condition, the abrasive velocity decreases gradually from inlet to outlet. For actual processing, the abrasive concentration can be selected between 50-60%. Based on the simulation analysis results, the parameters of abrasive flow polishing process were set, the orthogonal test method was adopted, and the test data were analysed by the polar analysis method the results showed that the priority order of the influencing factors of spiral groove polishing was: abrasive type > inlet speed > polishing time. Using SiC abrasive, inlet speed 0.5 m.s-1, polishing time30 min, the surface roughness of the spiral groove of cemented carbide twist drill after polishing is the minimum, reaching Ra0.189, which is far less than the design requirements.

Investigation of the Tool Wear Progression in Parting Technology

Martin Drbal, Stepan Kolomy, Josef Sedlak, Jan Zouhar, Jiri Vitek

Manufacturing Technology 2024, 24(6):901-913 | DOI: 10.21062/mft.2024.093

Parting-off stands as a fundamental method of turning, involving the cutting of the workpiece. The tool is most frequently a replaceable insert secured in a clamping bed. A pivotal set of observable metrics that ascertain the efficacy of a tool and its appropriateness for machining a specific material under defined cutting conditions is its durability. These durability parameters need to be determined for all new tools to ensure optimal performance and application in various machining scenarios. The primary objective of this research was analysis of the wear experienced by replaceable cutting inserts within the realm of parting technology. There were three distinct variants of replaceable cutting in-serts, all produced by esteemed manufacturer Dormer Pramet s.r.o. These cutting inserts were ap-plied in the parting process, consecutively machining two materials: bearing steel 100Cr6 and stainless steel 316L. The study not only encompasses the description of the cutting test procedure but also involves the meticulous execution of measurements and the subsequent analysis of the data procured from experimental activities. In the final phase of study, additional analyses are outlined to uncover the factors contributing to variations in certain obtained results. Those analyses, such as material or tool coatings analysis, provides more information about interplay between replaceable cutting inserts and the specific materials subjected to parting processes.

Influence of Using Cutting Fluid under the Effect of Static Magnetic Field on Chip Formation in Metal Cutting with HSS Tools (turning operation)

Umidjon Mardonov, Saidamin Khasanov, Andrey Jeltukhin, Shakhrizoda Ozodova

Manufacturing Technology 2023, 23(1):73-80 | DOI: 10.21062/mft.2023.006

This paper presents a new method of improving the material removal process in metal cutting. Chip formation plays an important factor in the metal cutting process and increasing its condition has a great impact on cutting machine details. Based on lubricating cooling conditions in the metal cutting process, a novel methodology is proposed to decrease the deformation that emerged in the material removal process while cutting cylindrical details in lathes. Application of stating magnetic field on flowing cutting fluids decreased the shrinkage of the chip in turning operation. Analytical and practical experiments show that the effect of cutting fluid under the influence of a static magnetic field decreased the shrinkage of the chip up to 20 % in comparison to the conventional use of cutting fluids in turning cylindrical pars with HSS tools.

The Effect of Strain Rate on the Friction Coefficient

Petr Svoboda, Miroslav Jopek

Manufacturing Technology 2024, 24(2):289-293

The Male and Cockroft ring compression test is one of the methods used to determine the coefficient of friction in forming. This method can be used to determine the coefficient of friction without the need to measure the force. This paper describes the results of the Male and Cockroft ring compres-sion test for the Hardox 450 material at different strain rates. The experiment was performed on ZD40 hydraulic press and CFA-80 pneumatic die hammer at the Faculty of Mechanical Engineering of Brno University of Technology. The test results were recorded in a calibration diagram. The results show that the strain rate has a significant effect on the coefficient of friction, specifically such that as the strain rate increases, the coefficient of friction decreases.

Experimental Investigation of Thermofriction’s Impact on Surface Hardness of Steel Products'

Falah Mustafa Al-Saraireh

Manufacturing Technology 2024, 24(4):645-651 | DOI: 10.21062/mft.2024.065

The impact of thermofriction on surface hardness has been investigated in this study. The metal disk method, which hardens parts' surfaces utilizing a metal disk, creates a hardened layer with the re-quired mechanical characteristics at a precise depth. The surface of treated products is one indica-tion of quality indicators. It has been noted that the thermal conductivity of the workpiece and tool material affects the irregular dispersion of heat in the processing zone. For evaluating the average integral rates of heating and cooling of the layer, the metal dependences have a significant impact on the form and properties of the friction-strengthened layer. It is discovered that several processing mode-dependent parameters affect power and density heat flow during hardening. It was found that when the feed rate increases, the hardened layer's depth decreases. The harder layer's depth increases as disk rotation speed (rpm) increases. when the disk rotation speed is increased to 265 rpm and the hardening depth (h) is 0.2 mm or less, it is said to be at N = (190-250) rpm. After heating the treated surface areas to a temperature between 130°C and 160°C above the critical temperature, the treated surface areas were then cooled applying compressed air to achieve the ideal surface hardness. After the hardening process, the surface hardness of blanks made of steel 1045 reached HRC 60, which is higher than conventional hardening.

Measurement of the Dynamic Load of the Cervical Vertebrae of the Human Spine – Pilot Experiment

Igor Žuravský, Martin Novák, Petr Vachata, Martin Sameš, Milan Chalupa, Adam Švásta, Martin Svoboda, Patrik Balcar

Manufacturing Technology 2024, 24(1):164-171 | DOI: 10.21062/mft.2024.006

The article deals with the experimental measurement of the load on the cervical vertebrae when driving a passenger car over bumps. The measurement was done experimentally. The load on the human spine was measured in the area of the C7 cervical vertebra and also in the area of the top of the head. Vehicle crossings over speed bumps. The measurement was carried out at different crossing speeds and at different heights of speed bumps. Three-axis acceleration sensors were placed on selected parts of the vehicle and on the human body. The proposed measurement methodology was verified by the conducted pilot experiment for the possibility of conducting further experiments. The results of the work showed that the crew of vehicles in road transport is more stressed than previous scientific findings indicate.

Effect of Solubility of Alloying Elements on Selected Properties and on the Structure of AlSi5Cu2Mg

Martina Sýkorová, Dana Bolibruchová, Marek Brůna, Mária Chalupová

Manufacturing Technology 2024, 24(5):817-826 | DOI: 10.21062/mft.2024.078

The paper deals with the solubility and influence of the melting method of alloying elements (Zr, Mo and Sr) on selected properties and structure of the hypoeutectic aluminum alloy AlSi5Cu2Mg. Alloy-ing elements in the form of master alloys (AlZr20, AlMo10, and AlSr10) were melted in two different methods. The first method consisted in melting the master alloy together with the batch material in an electric resistance furnace, the second method consisted in separately melting the master alloy in an induction electric furnace and then introducing the master alloy into the molten batch. The presence of alloying elements led to an increase in the porosity in all experimental alloys, which negatively affected the resulting physical and mechanical properties.

Production of Non-Compact, Lightweight Zinc-Tin Alloy Materials for Possible Storage of Liquid Hydrogen

Iva Nová, Milan Jelínek, Pavel Solfronk, David Koreček, Jiří Sobotka

Manufacturing Technology 2024, 24(1):87-97 | DOI: 10.21062/mft.2024.013

Unfortunately, in connection with the application of the Actavia anti-plagiarism system, we cannot accurately describe our paper, which deals with the production of non-compact materials based on zinc and tin alloys, which have a higher density than aluminium (ρ = 2700 kg.m-3 ) and its alloys, such as zinc alloys (ρ = 6980 kg.m-3 ) or tin (ρ = 7580 kg.m-3 ). Test samples were prepared from these materials, which were characterized by material non-compactness based on the use of NaCl particles. For this purpose, two different size groups of NaCl particles (3 to 5 mm and 5 to 7 mm) were used. In the production of non-compact metallic materials, it is assumed that half of the volume of the workpiece cavity will be occupied by NaCl particles and half of the volume of the work piece cavity will be filled with a melt of the relevant alloy (ZnAl4Cu1 or Sn89Pb). This is different from our previous experiments [24, 25]. In the case of this paper, the fabrication consisted in the fact that in a spe-cial preparation, the melt of the respective alloy was forced between the NaCl particles. The produced samples of non-compact material were analyzed and their specific gravities were determined. In a standard manner (as may be against the findings of the Actavia system), the microstructure was observed on an electron microscope and EDS analysis was also performed. It is anticipated that the non-compact materials thus produced from these two alloys will be used to produce not only filters but also bodies for liquid hydrogen storage.

Deformation and Velocity Wave Propagation in a Thin Isotropic Plate

Frantisek Klimenda, Blanka Skocilasova, Jan Skocilas, Josef Soukup

Manufacturing Technology 2024, 24(3):393-409 | DOI: 10.21062/mft.2024.040

The propagation and velocity of the deformation wave in the thin isotropic plate is investigated. The deformation is induced by the stroke of impact body onto the facial surface of the plate. The plate is supported perpendicularly. The excitation of the plate oscillation is initialized by a unit force (Heavi-side’s jump). The impact body has a rounded facet by radius c = 2.5 mm. Hook's material model and Kirchhoff’s and Flüegge’s geometric model have been investigated. The analytical solutions for both models are presented. The MATLAB script has been assembled to solve material and geometrical mod-els. The results were compared for two selected points on the surface of the plate. Plate deformation was recorded at two points T1 (at a distance of 20 mm from the impact location on the x axis) and T2 (at a distance of 20 mm from the impact location on the y axis).

Proposal for Evaluating the Efficiency of Production Processes Using External and Internal Key Performance Indicators

Erika Sujová, Daniela Vysloužilová, Ivan Babic

Manufacturing Technology 2024, 24(3):440-447 | DOI: 10.21062/mft.2024.050

The paper focuses on proposing a method for implementing key performance indicators (KPIs) to assess the effectiveness of manufacturing processes. For the evaluated processes of precision parts machining, the share of non-conforming products was proposed as a KPI, evaluated as both an exter-nal and an internal indicator. The external indicator EXTppm expressed the quantity of faulty prod-ucts to the volume of production. Its monthly development during 2022 was evaluated. The internal KPI represented the internal share of non-conforming products INTppm during 2022 which was re-lated to the order of part A. Towards the conclusion causes for not attaining the targeted KPI values are pinpointed, and recommendations are put forth to enhance the productivity of manufacturing processes.

Analysis of the Torsional Strength of Selected Photopolymers Additively Manufactured Using Polyjet Technology

Jacek Bernaczek, Mariusz Dębski, Małgorzata Gontarz-Kulisiewicz

Manufacturing Technology 2024, 24(6):865-870 | DOI: 10.21062/mft.2024.094

PolyJet technology, based on the printing and photopolymerization of model material, is currently, along with stereolithography or 3SP (Scan, Spin and Selectively Photocure), the most commonly used rapid prototyping method based on optically active resin. The article presents the results of torsional strength tests of samples made of optically active resins VeroDentPlus-MED690, VeroClear-RGD810, and Rigur-RGD450 by Stratasys in PolyJet technology. The samples were prepared in HQ (High Quality) mode with a layer height 0.016 [mm]. The tests included a static torsion test using a specialized research stand by the Department of Mechanical Engineering of the Rzeszów University of Technology. The scope of research significantly expanded the standard procedure, which complements the material data available with significant functional parameters due to the use of models. The results of the torsional strength analysis determined in the research process can be used to define the potential application area of the materials in question - optically active resins and their processing techniques for the production of parts subject to complex loads, i.e. machine shafts, clutches, and gear hubs.

The Effect of Employing an Optimal Web Velocity Profile on Transverse Vibrations in Roll-to-Roll Manufacturing

Kadhim A. Jabbar

Manufacturing Technology 2024, 24(2):192-196

The quality of web products is significantly affected by the running velocity of a process line, especially during the stages of start-up and shutting down of a web processing line. At these stages, a remarkable transverse variation (web flutter) are observed due to employing improper input velocity. Web flutter may cause some web defects such as wrinkles, poor printing and even web breakage. Therefore, employing an optimal web velocity profile is crucial to minimize web transverse vibrations during the transport of the web through different processing sections in a web process line. In this paper, an optimal velocity profile along with common velocity profiles (widely used in industry) have been utilized in a running web line to demonstrate the effect of web transport velocity on transverse vibrations. Comparative experimental results are presented and discussed.

The Microscopic Study of the Evolution of the Phase Transformation in the Tin after the Indentation of an Inoculator

Alena Michalcová, Šárka Msallamová, Dominika Fink, Jiří Kubásek, Martin Friák

Manufacturing Technology 2024, 24(1):83-86 | DOI: 10.21062/mft.2024.007

This paper describes β-Sn to α-Sn transformation in its initial phase. This process is also known as a tin pest and currently it causes problems mainly in the field of soldering materials. To avoid misrepresenta-tion of the results of artificial ageing of the samples; we have decided to use historical materials for our study. A sample from historical organ pipes was indented by naturally formed α-Sn polycrystalline parti-cles by the load of 1 kg. The sample in the initial state was observed by SEM and analysed by EBSD mapping. The position of inoculator particles was documented again by SEM observation. Subseqently, the sample was freezed at -50 °C. The evolution of cracks started after 2.5h in the vicinity of indented α-Sn particle. After 5 h of freezing, new cracks were observed also in the untouched parts of the sample. The crystallografical interconnectedness was not proven for polycrystalline samples.

The Mechanical Analyses and Structural Optimization of CSMC Preload System under Multi-load Cases

Xianewei Wang, Haikuo Zhao, Fei Xie, Chenyang Li, Xiulian Li

Manufacturing Technology 2023, 23(5):732-738 | DOI: 10.21062/mft.2023.075

In order to accumulate experience in the design and manufacturing of the toroidal field coils for the China Fusion Engineering Test Reactor, a model coil of mixed Nb3Sn-NbTi superconducting magnet with a maximum magnetic field variation rate of 1.5 T/s has been developed at the Institute of Plasma Physics, Chinese Academy of Sciences. The preload system, as one of the key components of the model coil, plays a crucial role in maintaining the overall integrity and stability of the model coil. First the magnetic field and electromagnetic forces of the model coil under extreme conditions are calculated based on Maxwell's equations. Then, the mechanical performance of the model coil at room and cryogenic temperatures is analyzed. To addressing the issue of excessive stress in the preload components of the model coil under preload, several optimization design schemes are proposed and iteratively analyzed. Finally, stress linearization is performed, and stress evaluation is conducted based on the analytical design. The assessment results indicate that certain optimization schemes enable the preload components to fully meet the operational requirements at both room and cryogenic temperatures. The outcomes presented in the paper will provide reference for the subsequent design and manufacturing of the central solenoid coil.

Influence of the Orientation of Parts Produced by Additive Manufacturing on Mechanical Properties

Vladimír Bechný, Miroslav Matuš, Richard Joch, Mário Drbúl, Andrej Czán, Michal Šajgalík, František Nový

Manufacturing Technology 2024, 24(1):2-8 | DOI: 10.21062/mft.2024.021

Binderjetting technology works on the principle of line injection moulding, using metal powder and liquid binder as input material, which is uniformly applied by print heads to the previous layer using a nozzle. By successively applying each layer, the desired shape of the designed component is obtained. The technology offers a large number of advantages which include the possibility of using any printing powder that may contain functional graded materials. Furthermore, it is a green manufacturing technology where we can reuse unused metal powder in the next printing cycle after following the prescribed process. As a result, we characterize this technology as a near-waste-free production of metal parts. The research aims to analyse the impact of different orientations of printed parts within the workspace on the mechanical properties of the resultant components. Additionally, the study aims to compare these mechanical properties with the specifications recommended by the metal powder manufacturer and findings from previous research studies. Based on the experimental measurements carried out, we can conclude that the influence of the orientation of the parts in the workspace has only a minimal effect on the mechanical properties of the manufactured parts.

The Impact of Cryogenic Temperatures on the Hardness and Tribological Properties of Cobalt Alloys

Jakub Mráz, Totka Bakalova

Manufacturing Technology 2024, 24(4):626-635 | DOI: 10.21062/mft.2024.057

This article explores the effect of cryogenic temperatures on the properties of cobalt alloys, specifically Stellite 6 and Stellite 12. These alloys are commonly used in applications that require resistance to me-chanical, thermal, and chemical wear. In this study, the focus is on the valve seats for internal combus-tion engines, which are made from cobalt alloys and undergo a freezing process before assembly into the cylinder head. The purpose of freezing is to reduce the diameter of valve seats, making them easier to fit into the cylinder head. However, the length of time spent in freezing can significantly affect the hardness and tribological characteristics of the material.

Effect of Normal Ageing in Bundle on the Mechanical Properties of Tempcore Treated Reinforcing Steel Rebar

Mohamed Karroum, Marwa A. Abbas, Ahmed Ramadan, Mohamed A. Gepreel

Manufacturing Technology 2024, 24(5):779-790 | DOI: 10.21062/mft.2024.088

Reinforcement steel rebar is produced by several ways but most importantly the tempcore process. Due to mass production in steel rolling plants, the rebars are gathered after tempcore process at a specific temperature in bundles stack in the warehouse. The bundling temperature varies from 200 to 300 o C. The rebars need relatively long time, up to one day, to reach the room temperature in the bundles stack. This work investigates the effect of prolonged ageing time on the rebars mechanical properties after the tempcore process of both ageing in bundle and designed artificial ageing. The results of mechanical properties of ageing in bundle compared to the artificial ageing were found to be in good agreement. The yield and tensile strengths were found to decrease by 6.3 and 2.1 %, respectively, due to artificial ageing. However, the elongation and the tensile to yield ratio increased by 17.6 and 4.8 % respectively.

The Influence of Industrial-Scale Pack-Boroding Process Time on Thickness and Phase Composition of Selected Cold-Work Tool Steels

Jakub Jopek, Marek Góral, Barbara Koscielniak, Kamil Ochal, Marcin Drajewicz, Magdalena Mokrzycka, Tadeusz Kubaszek, Kamil Dychton, Kamil Gancarczyk, Andrzej Gradzik, Pawel Kwasniewski, Wojciech Gluchowski

Manufacturing Technology 2023, 23(5):630-637 | DOI: 10.21062/mft.2023.069

The boride coatings are characterized by attractive set of properties such as high hardness and wear resistance, corrosion resistance in higher temperatures and no wettability by liquid metals like alumi-num and zinc. This type of coating might be used for manufacturing of different parts from tool steels. In present article the influence of pack boriding time (2,4,6h) on microstructure and phase composition of obtained coatings is scrutinized. The pack boriding process was conducted on two groups of cold work tool steels: low-Cr content: 145Cr6, 90MnCrV8, 60WCrV8 and high-Cr content: X165CrV12, X153CrMoV12. The commercial boriding pack Ekabor 2 was utilized and the process was carried out using industrial CVD device (Bernex BPX Pro 325S). The conducted research showed that the boride coatings formed on the substrate of high-chromium steels were characterized by a lower total thick-ness. On low-chromium steels, FeB phase was discontinuous as an irregular islands located in the near-surface area. On the other hand, for high-chromium steels, a continuous layer of needle-like borides was formed.

Analysis of Static and Dynamic Characteristics and Lightweight Design of Titanium Alloy Frame

Bin Zheng

Manufacturing Technology 2024, 24(3):507-519 | DOI: 10.21062/mft.2024.053

In response to the problems of insufficient strength and stiffness, as well as large weight in traditional car frames, this article takes titanium alloy frames as the research object. Based on the analysis of static and dynamic characteristics, a lightweight design is carried out to meet the design requirements. Firstly, static analysis was conducted on the frame structure under four different working conditions using the finite element analysis method to study its stress distribution and deformation under different loads and road conditions. Study the natural frequency and vibration mode of the frame through modal analysis, providing a basis for subsequent optimization design. Through harmonic response analysis, explore the changes in the amplitude and frequency of the frame during use. On this basis, topology optimization and lightweight design are carried out on the frame structure to reduce the weight of the frame and improve its strength and stiffness. Finally, validate and compare the optimized frame to explore the feasibility and superiority of the optimization plan. The research results show that the optimized frame weight has been reduced by 13.76%, the maximum stress has been reduced by 5.19%, and the maximum deformation has been reduced by 0.37%, effectively reducing the frame mass. This provides a way of thinking about the static and dynamic characteristics analysis and topology optimization design of automotive frames.

Analysis of the Basic Characteristics of the Working Accuracy of the Atomic Diffusion Additive Manufacturing ADAM Process by Comparison with the Selective Laser Melting SLM Process

Andrej Czan, Tatiana Czanova, Jozef Holubjak, Martin Novak, Natalia Czanova, Andrej Czan, Dominik Krisak

Manufacturing Technology 2024, 24(1):15-27 | DOI: 10.21062/mft.2024.015

Atomic Diffusion Additive Manufacturing (ADAM) is a progressive layering process based on metallic materials with a plastic binder designed to extruse the material. The ADAM process can be classified as an indirect additive manufacturing process in which a solid fiber of metal powder enclosed in a plastic binder is applied. After creating a 3D object by the ADAM process, the excess plastic binder is removed in the cleaning chamber and vacuum sintering of the 3D object is performed. This work aims to provide a preliminary characterization of the ADAM process and compare the achieved results with the application most implemented so far in additive manufacturing for metal 3D objects using Selec-tive Laser Melting SLM. In particular, the density and microstructure of the applied process and mate-rial 17-4PH are studied, while optimal or recommended technological parameters of production facili-ties are applied. Furthermore, the dimensional accuracy of the ADAM process is observed, which is evaluated by means of IT accuracy levels according to the ISO reference artifact. Due to the applied AM process, the final character of a 3D object depends on technological parameters. The weight of a 3D object is low compared to the material processed by additive manufacturing processes in a powder bed. The dimensional accuracy and roughness of the surface depends on the geometry, orientation, and position of the individual shape specifications of the 3D object. Additive technologies generally achieve a degree of accuracy of approximately IT12 to IT13, which is comparable to traditional semi-finished metal manufacturing processes.

Analysis of the Impact of Modernization of Machinery on the Quality of Castings Using Quality Management Tools

Krzysztof Knop, Pavol Gejdoš

Manufacturing Technology 2024, 24(2):207-218

Today's manufacturing industry, especially in the context of the metals industry, is constantly evolving towards ever more advanced technologies and efficient production practices. In this context, machinery modernization is becoming a key element in improving manufacturing processes. This article focuses on analysing the impact of machinery modernization on casting quality, using selected quality manage-ment tools. The article presents an analysis of the effects of the implementation of modern technology, automatic casting machines, on the quality of castings production. Using quality tools such as the Ishi-kawa diagram, Pareto-Lorenz and the FMEA method, the main causes of casting nonconformities, the frequency of occurrence of these nonconformities and the risks associated with them were identified for periods before and after the implementation of machine park modernization. The measurable benefits associated with the introduction of modern foundry technology in terms of improved casting quality were showed. Using quality tools, the quality improvement achieved was determined indirectly, while the level of improvement in casting quality after the modernization of the machine park was showed directly using the defect rate. It was also shown that, despite an increase in production efficiency and the level of quality of the manufactured products, the introduction of the new technology generated new quality challenges in the context of maintaining the stability of the casting process parameters as a result of a jump in productivity levels. The paper highlights the need to balance production efficiency with atten-tion to casting quality, which was an important issue for the foundry studied.

An Investigation into Forming of Gears Using Rotary Forging Process

Ayman Ali Abd-Eltwab, Walid Elsyed Ayoub, Mohamed N. El-Sheikh, Essam Khalaf Saied, Nouby M. Ghazaly, Gomaa A. A.

Manufacturing Technology 2024, 24(4):539-551 | DOI: 10.21062/mft.2024.068

Gears and toothed parts are significant components in power transmission systems. These parts usu-ally manufactured by traditional methods such as machining by milling or forming by rotary forging. In this study, the forming of solid gears or toothed parts using a forging process that combines rotary forging and ballizing technique. The specimens were placed inside the die with excessive volume to fill the toothed part in the die. The forming tool applies pressure to the specimen while rotating it together with the die by the lathe machine chuck, while the tool advances continuously in the direc-tion of the die. This reduces height of the specimen and increases its diameter, causing metal flow to fill die cavity teeth and form the gear or toothed part required for production. Two sets of experi-ments were performed. In the first set, optimization for the appropriate volume of four different sizes of dies and four forming tools was conducted. While in the second set, the effects of forming process variables on the forming load and tooth filling percentage was studied. The results showed that the best tooth filling ratio happened with specimens size of 1.2 to 1.4 times the volume size of the desired tooth for filling. The results also revealed that the forming speed, die size, and forming tool diameter affect the filling ratio and forming load.

The Influence of the Choice of Machining Strategy on Production Technology

Martin Reznicek, Cyril Horava

Manufacturing Technology 2024, 24(1):117-130 | DOI: 10.21062/mft.2024.014

This paper deals with the issue of selecting different machining parameters in the CAM system Siemens NX 1946. The issue of choosing between a solid end mill, milling cutter, and a high-feed tool when machining simple rectangular and rugged cavities concerning time and residual material is solved here. The chosen material was 1.1730, which is a basic material for the production of moulds without heat treatment. The paper deals with the issue of choosing the size of tool feed into the cut and its influence on the formation of the machining path depending on the depth of the cavity. The size of the residual material depends on the machining strategy and the choice of the plunge method into the material with regard to the total machining time. Performed simulations and experiments have shown a significant impact in individual settings and, thus, on the cost of machining components of such shapes.

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