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Results 301 to 330 of 1457:

Concept Design of a Tram Bogie with Atypical Suspension

Vladimír Hauser, Kateryna Kravchenko, Mária Loulová, Olena Nozhenko, Jozef Haru¹inec, Alfréd Pavlík, Oleksij Fomin

Manufacturing Technology 2019, 19(1):42-48 | DOI: 10.21062/ujep/242.2019/a/1213-2489/MT/19/1/42

In the urban railways environment, there is considerable stress of the track due to operation, which results in extensive deformation of the track geometric position, wear of the rail heads, expansion of the free channel of the track, leading to an increase in steering forces in the rail-wheel contact and further worsening of the situation. The authors perceive this situation primarily as a consequence of an inappropriate bogie concept of the operating vehicles - not of the track quality. The article focuses on designing a new bogie concept that takes into account the specific environmental conditions for which it is intended. The presented bogie design is characterized by the mounting of the frame on the wheelsets by means of three bearing boxes and the presence of a mechanism for adjusting the radial position of the wheelsets during ride in track arcs. This is a new, unconventional solution for which a number of patent applications have been filed. Simulation analyzes of vehicle ride with the designed bogie are currently underway. On the basis of the first results, it is foreseen that the design will increase the life of the track several times, reduce the energy consumption of vehicles and the environmental load of the environment through the transport system.

Acoustic Characteristics of Composite Structures Used in Train

Martin Juricka, Ladislav Fojtl, Soòa Rusnáková, Eva Juøièková

Manufacturing Technology 2020, 20(3):335-341 | DOI: 10.21062/mft.2020.043

This paper presents a study focused on sandwich structures as well-known train construction materials that are composed of two thin and rigid face sheets and a thick, low-density core material. For trains, the wheel-rail inter-face is the main source of noise, and the wheel-rail roughness, especially in the presence of rail corrugation, is the main excitation source transmitted to the interior and area for passengers. The purpose of the study is to optimize the acoustic properties of a composite sandwich panel used for train floors and walls. Sound absorption coefficient (?), noise reduction coefficient (NRC) and Transmission loss (TL) evaluations have been implemented and experimentally validated on a typical sandwich material used for trains. The opportunity to use a different material can be concretely calculated and modified for critical frequency ranges. Sound transmission loss levels of the structural components as the floor and wall of the train body, which are required of producers and cus-tomers, were tested in acoustic laboratory and acoustic devices according to ASTM and ISO standards. It is demonstrated that, for honeycomb and cork sandwich panels, acoustic response is not sensitive to cell size. For foam core sandwich panels, it is observed that different compositions with thin layers are effective in the fre-quency range of 50 - 1000 Hz.

Degradation of a Grinding Wheel when Grinding Cermet Materials and Its Influence on the Grinding Process

Tomas Baksa, Pavel Adamek, Ondrej Hronek, Miroslav Zetek

Manufacturing Technology 2019, 19(1):9-13 | DOI: 10.21062/ujep/236.2019/a/1213-2489/MT/19/1/9

This article deals with the experimental grinding of cermet materials. Two types of cermet materials from different suppliers were ground under constant grinding conditions using a diamond grinding wheel. The main aim was to determine the influence of the grinding on the degradation of the grinding wheel and changes in the grinding process. Both types of cermet were ground with the same strategy and the same number of passes. The grinding wheel was analysed during grinding using an optical scanning device to observe the changes on the grinding wheel surface. Clogging and wear of the grinding wheel occurred on the surface as the amount of material removed increased. All grinding tests were carried out without dressing or truing of the grinding wheel. Degradation of the grinding wheel had a big influence on the grinding process in terms of the spindle load during grinding. The roughness of the ground surface was also measured using the optical scanning device. The results from this work will be used for further research of cermet grinding.

Research on optimization of a high precision hydrostatic turntable

Lai Hu, Yaolong Chen

Manufacturing Technology 2020, 20(6):755-762 | DOI: 10.21062/mft.2020.119

This paper mainly studies the hydrostatic turntable of precision milling and grinding compound machining center in aerospace processing equipment, and innovatively designs and analyzes the mesa. It is proposed to replace the traditional 40Cr with imported marble for the mesa. Firstly, the vibration model of the hydrostatic turntable is carried out. ANSYS Workbench software is used to compare and analyze the original and marble materials. In the process, the static characteristics and the difference of first-order modes of the two materials are compared. In addition, the analytical results are used for manufacturing. The results show when the applied force reaches the limitation 29400N, the maximum displacement of 40Cr increases sharply to 8.9406μm; while the marble material reaches 2.6μm. Meanwhile, it is obtained that the power consumed by marble is reduced by 39.12% compared with 40Cr. The weight of marble is reduced by 39.36% compared with 40Cr. Marble is about 21.59% higher than 40Cr in the comparison of vibration mode results

Modelling of Roller-raceway Contacts in the Slewing Bearing Taking into Account Asymmetrical Load Transfer Through a Roller

Marek Krynke

Manufacturing Technology 2019, 19(6):979-983 | DOI: 10.21062/ujep/406.2019/a/1213-2489/MT/19/6/979

During the operation, a slewing bearing is always subjected to a set of combined loads. It is the source of deformation of ball-raceway contacts, rings, and even supporting structures. In practice, deformation of rings and supporting structures is often neglected for simplification, that is, they are supposed to be ideally stiff. To take elasticity of rings and supporting (fixed) structures into consideration, the finite-element method (FEM) is applied. In slewing bearings, a great number of contact pairs are present on the contact surfaces between the rolling ele-ments and raceways of the bearing. In order to improve the computational efficiency of load distribution of large roller slewing bearing, a computa-tional model using one-dimensional finite elements (nonlinear elements) is presented in this paper. In this model, each roller is simulated by a group of nonlinear elements truss, which has the same load-deformation perfor-mance with solid roller-raceway contacts. The results show that a group of parallel springs can be used to replace the solid roller and simulate the line contact performance between the roller and raceway. Obtained results are presented as graphs.

The Study of the Distribution of Carbon Black Filler in Rubber Compounds by Measuring the Electrical Conductivity

Dana Bako¹ová

Manufacturing Technology 2019, 19(3):366-370 | DOI: 10.21062/ujep/297.2019/a/1213-2489/MT/19/3/366

This study deals with distribution of carbon black fillers in rubber compounds using electrical conductivity measurements. Three rubber compounds samples were heated in resistive furnace in temperature interval 40-80°C and electrical current was measured, while voltage was constant. All samples showed a decrease in electrical conductivity with decreasing temperature, which is characteristic of semiconductors and insulators. On the other hand the large variance of activation energy can be seen for electric transport in different areas of the temperature dependence of the direct electrical conductivity. These quasi-linear areas were selected, linear regression was used and corresponding activation energy was calculated. The number of the identified areas was changing, and hence the number of conductivity mechanisms was changing as well. Clearly it can be concluded that all three samples show inhomogeneity of distribution of filler, which can be seen from the variance of values of the activation value of electric transport.

Parallel Optimization of the Balancing and Sequencing for Mixed-model Assembly Lines

Wei Zhang, Liang Hou, Yawen Gan, Changhua Xu, Xiangjian Bu, Haojing Lin

Manufacturing Technology 2019, 19(3):537-544 | DOI: 10.21062/ujep/325.2019/a/1213-2489/MT/19/3/537

The traditional Mixed-model Assembly Lines (MMALS) balancing and sequencing serial design methods are difficult to adapt to rapidly changing requirements. From the perspective of the parallel design of balancing and sequencing, a mixed integer linear programming model for MMALS balancing and sequencing is proposed. An improved particle swarm optimization (PSO) algo-rithm was proposed, in the process of updating the optimal solution, the simulated annealing (SA) algorithm is added to make it possible to jump out of the local optimum with a certain probability and expand the solution selection to the entire population. Based on the algorithm, random coding and ascending decoding methods are proposed, the number of products and the number of tasks are coded and decoded at the same time. Verify the effectiveness of the algorithm by an example.

Formwork Support Design of Roof of Subway Interval Engineering Based on Finite Element Analysis

Sujuan Li

Manufacturing Technology 2019, 19(6):993-997 | DOI: 10.21062/ujep/408.2019/a/1213-2489/MT/19/6/993

The design of the formwork support for a certain section of the Beijing subway project was carried out in this paper. And the disk lock formwork support was used in the engineering.It was analyzed on the the design of the formwork support for the roof with the thickness of 1.5m of the interval engineering. The manual calculation and the sap2000 finite element analysis were also used in the paper.The effect of the diagonal brace and its number were analyzed in addition to the design of the formwork support. It was showed that the axial force of the standing tube tends to be uneven with the increase of the number of slant bars in the framework. And the axial force of the standing tube connected to diagonal brace is larger than that of the framework without brace significantly. So it will be dangerous to the framework without considering the effect of it by the manual calculation.

Possibility of Using Eddy Current Evaluation of the Heat Treatment of Steel

Petr Bene¹, Vojtìch Prùcha, Jiøí Hájek, Vilém Vítovec

Manufacturing Technology 2019, 19(3):371-374 | DOI: 10.21062/ujep/298.2019/a/1213-2489/MT/19/3/371

There are a large number of special methods for exploring the internal condition of materials on the basis of eddy currents. A major use of this method can be seen in surface engineering, particularly in studying some state quantities of surface integrity. It is also an irreplaceable tool in surface engineering. The reason is that no other affordable method provides information on both the surface and the sub-surface regions, as the latter are difficult to reach by most other inspection methods. It must be noted that the sub-surface region is significant, and dictates, to a large extent, the behaviour of the overlying surface. This article explores another non-traditional application of eddy current inspection. The study presented here involves a use of this non-destructive testing method for carburizing verification and for detecting of amounts of retained austenite.

Modal Analysis of the Tubular Space Frame of a Formula Student Race Car

Attila Schweighardt, Balázs Vehovszky, Dániel Feszty

Manufacturing Technology 2020, 20(1):84-91 | DOI: 10.21062/mft.2020.013

This document presents the characterization of the dynamic mechanical properties of a racecar's frame. First, it introduces the applicability of modal analysis, then the modal analysis of a lightweight vehicle chassis will be detailed, which is the focal point of this paper. This analysis was performed to determine some of the modal parameters, in order to reduce the noise of the vehicle, the probability of a component failure and to improve the comfort. The simulation part of the applied analysis was based on dynamic FEM (Finite Element Method). The measurement part of it was based on measuring the FRFs (Frequency Response Functions), with the help of accelerometers fixed at the nodes of the frame. The excitation signals were provided by a shaker connected to the chassis. In order to provide good quality results, the processing and evaluation of the simulated and measured data has to be done properly, which is discussed in detail. However, one dominant factor of a modal analysis is to find the optimal measurement setup. For this reason, the details of the measurement setup will be included. Hence one of the goals was to improve the coherence curves of the FRFs. Thanks to the presented techniques, the coherence curves managed to be improved and the results of the simulation and the measurement were found to be in good agreement.

Assessment of Readiness for Industry 4.0 Implementation in Ceramic Industry

Tomas Kellner, Martin Necas, Michal Kanak, Martin Kyncl, Jiri Kyncl

Manufacturing Technology 2020, 20(6):763-770 | DOI: 10.21062/mft.2020.110


This paper focuses on the implementation of principles of Industry 4.0 concept to the ceramic industry. The topic of this paper is to address the problematics of the implementation of processes and elements of digitization within the Industry 4.0 concept into the ceramic industry. Firstly, thorough literature and best-practice research will be discussed. Based on the state of current knowledge, the concept of the Industry 4.0 Readiness Model for Refractory will be presented. The model’s main focus is on the readiness of current business structures, processes and technical and economical situation. It will provide the necessary analysis and insight into the potential company’s processes and background. Based on this analysis, it will be possible to define the main obstacles for future digitalization and automation within Industry 4.0 the concept in Refractory industry. On the foundation of data obtained by Industry 4.0 Readiness Model for Refractory, it will be possible to implement the Industry 4.0 solutions with the highest added value to a specific company, based on its current state. The main purpose of this paper is to summarize and discuss key parameters and framework for Industry 4.0 Readiness Model for Refractory and its connection to future implementation of Industry 4.0 features within the ceramic industry.

Influence of Si and Cu content on tempering and properties of 54SiCr6 steel

Pavel Salvetr, Zby¹ek Nový, Aleksandr Gokhman, Jakub Kotous, Jan Zmeko, Petr Motyèka, Jaromír Dlouhý

Manufacturing Technology 2020, 20(4):516-520 | DOI: 10.21062/mft.2020.079

The 54SiCr6 steel belongs to spring steels which excel high strength and at the same time reaches high values of reduction of area and sufficient value of elongation. Nowadays, new methods are searched and examined how to get better properties from materials, higher strength and toughness, longer fatigue resistance or better corrosion properties. In the case of silicon-chromium spring steels, innovative heat treatments are investigated such as quenching and partitioning which enables to achieve higher ductility of steel due to higher content of retained austenite. The way of modification of the chemical composition of the 54SiCr6 steel was chosen in combination with conventional heat treatment composed of quenching and tempering to get better properties. The materials with in-creased content of copper to 1.5 wt. % and silicon to 2.5 wt. % were prepared. The influence of alloy-ing elements on microstructure and mechanical properties was followed up to the tempering temper-ature of 400 °C.

Modeling and Simulation of Composite Materials for SLS-Based 3D Printing

Md Hazrat Ali, Gaziz Yerbolat, Anuar Abilgaziyev

Manufacturing Technology 2020, 20(2):135-142 | DOI: 10.21062/mft.2020.041

This paper discusses the modeling and simulation results of a new multi-material for a cost-effective Selective Laser Sintering (SLS)-based 3D printer. As this technology utilizes several materials, the me-chanical property analysis of multi-materials is crucial for manufacturing an object with the desired physical characteristics. Firstly, the development of a database of the SLS 3D printing materials is ac-complished and based on the mechanical properties of materials, this optimization technique is proposed. Secondly, enhancement of physical property by stiffeners is considered and based on the stiffening tech-nology, and an alternative optimization method proposed. Finally, two different material minimization methods are discussed in this research. The first method is based on the embedded materials with desired mechanical properties for enhancing the mechanical properties of the printed objects, which are twice optimized by this method with increased material saving. The second method is designed to use stiffeners to improve the stiffness characteristics of the materials, and then, perform material optimization. This method is effective with more suitability to complex composite geometries. Thus, the methods help to reduce materials used as well as the production cost in 3D printing technology.

Evaluation of the Strengthening Effect of Different Surface Treatment Techniques in Steel Crankshaft Manufacturing Industry

Songsong Sun, Xiaolin Gong

Manufacturing Technology 2022, 22(6):747-753 | DOI: 10.21062/mft.2022.087

At present, electromagnetic induction quenching and nitriding are two commonly used surface strengthening approaches applied in improving the strength of the steel parts. In this paper, a comparative study was proposed to research the strengthening effect of these two technologies in improving the fatigue strength of steel crankshaft. First a modified statistical analysis approach of the fatigue limit load was proposed to obtain the distribution of the fatigue limit load. Then two types of steel crankshafts were selected to be the object of research and treated by these two techniques. Finally the standard T and F hypothesis testing methods were conducted in evaluation the strengthening effect. The results showed that compared with the nitriding approach, the electromagnetic induction approach can improve the fatigue strength of the steel crankshaft more obviously, thus is more suitable for engineering applications.

Parametric Optimisation of Micro Plasma Welding for Wire Arc Additive Manufacturing by Response Surface Methodology

Nor Ana Rosli, Mohd Rizal Alkahari, Faiz Redza Ramli, Mohd Fadzli bin Abdollah, Syahibudil Ikhwan Abdul Kudus, Safarudin Gazali Herawan

Manufacturing Technology 2022, 22(1):59-70 | DOI: 10.21062/mft.2022.001

High deposition rate with minimal heat input is one of the primary emphases in wire arc additive manufacturing. This study aims to determine the optimal input parameters of micro plasma welding for single-layer deposition. The stability of a single layer is crucial as it serves as the foundation relative to the deposition of layers to avoid a discontinuous multi-layer material. The study focuses on wire feeding speed, welding speed, and pulse and their interaction between the input and response variables. Based on the study, the regression equation between the three key parameters and the response using the Box-Behnken Design response surface methodology was proposed. The outcome demonstrates that the op-timized sample deposition produces a smooth surface appearance with no apparent defects.

Stress Corrosion Cracking and Copper Alloy Products

Vladivoj Oèená¹ek, Jan Lu¹tinec

Manufacturing Technology 2022, 22(1):39-44 | DOI: 10.21062/mft.2022.012

Stress corrosion cracking (SCC) is a common cause of structural failure. The simultaneous action of the corrosive environment and tensile stresses creates cracks that have an intercrystalline or transcrys-talline character. These are cracks with a fragile morphology of the fracture surface without signs of plastic deformation in their vicinity. SCC cracks occur in several alloys. This paper focuses on copper alloys in which this type of failure occurs frequently. Examples from practice show cases where the occurrence of SCC violation was related to the conditions of use of components and their production technologies. The paper does not aim to capture all the influences associated with the occurrence of SCC failure of copper alloy products.

Influence of the Welding Process on the Quality of PVC Frames

Mateusz Wygoda, Marcin Paprocki, Wac³aw Adamczyk

Manufacturing Technology 2022, 22(3):356-366 | DOI: 10.21062/mft.2022.037

This paper focuses on the technical and practical aspects arising during the process of window production. One of the phases in the window manufacturing process is welding PVC corners. Therefore, the main subject is flexural strength of PVC welds in the context of the required quality. In the first part of the paper, the authors highlighted the factors and conditions of the welding process and their influence on the final properties. In the next part of the study attention is mainly paid to the temperature control, which is often the cause of quality problems with welding corners. The welding process was conducted with the use of three types of welding machines, i.e. single-, double- and four-head units. In each case, the welding temperature was set in the controller of the machine; at the same time, the contact temperature measurement was taken. The next step was verification of the influence of temperature on the welded PVC corners by measuring the bending force according to PN-EN 514:2002. Additionally, the authors present the DIC (Digital Image Correlation) method used to assess displacements and strains for a selected case in the process of bending PVC corners. The study provides a basis for discussion and remarks about practical advice and identification problems associated with the durability of PVC welding in industrial processes.

The Effect of Boriding and Heat Treatment on the Structure and Properties of 100Cr6 Steel

David Bricín, Antonín Køí¾, Jan Novotný, Zbynìk ©pirit

Manufacturing Technology 2022, 22(1):2-9 | DOI: 10.21062/mft.2022.003

The main aim of this case study is to present the changes caused by heat treatment on the structure and properties of 100Cr6 steel by annealing, hardening, and tempering in combination with previous chemical-heat treatment (CHT) by boriding. The boriding causes changes to the microstructure of the steel samples, which include a change in the morphology of the deposited cementite and a change in the volume of the chromium carbide particles. The cementite is transformed from its original granular form to a lamellar form. An increase in the proportion of chromium carbide particles in the sample occurs due to the higher affinity of chromium for carbon. This leads to precipitation of chromium carbides rather than carbides of iron. A multi-phase diffusion layer Fe2B-FeB with a thickness of 31 ± 2.8 µm is formed during boriding, with a typical tooth-like texture. Although the diffusion layer does not have the same toughness and resistance as the single-phase Fe2B diffusion layer, samples after boriding increase their resistance to tribological abrasion by 29 % compared to samples without this treatment. After quenching and tempering of the borided samples, a maximum tensile strength of Rm = 1779 MPa is measured. Compared to samples which are only quenched and subsequently tempered, this is an increase in tensile strength of about 59 %.

Multi-Response Optimization of Friction Stir Welding of AA2050 Using Response Surface Methodology Coupled with Grey Relational Analysis and Principal Component Analysis

Raju Kamminana, Venkata Subbaiah Kambagowni

Manufacturing Technology 2022, 22(2):156-167 | DOI: 10.21062/mft.2022.016

The third generation aluminium-lithium alloy AA2050 finds wide applications in defence and aircraft industries by virtue of its high strength-to-weight ratio and excellent corrosion resistance. Friction stir welding (FSW), relatively novel technique, is more suitable to join this alloy compared to other conventional fusion welding techniques. In this work, the overall quality of the weld joint was decided from the higher values of tensile strength, yield strength, percentage elongation, hardness of weld zone, hardness of heat affected zone, bending load and lower value of width of heat affected zone. The optimal (combined) design was used to design the experiments with four numeric factors (traverse speed, rotational speed, tilt angle and shoulder diameter) and a categoric factor (tool pin profile). The multi-response optimization problem was reduced into a single-response optimization problem using grey relational analysis (GRA); principal component analysis (PCA) was used to assign optimal weighting values for the responses in the process of dimensionality reduction. Mathematical model for the reduced single response, which can be perceived as overall weld quality, was developed by the response surface methodology (RSM) and the optimization of process parameters was also carried by the RSM. Analysis of variance (ANOVA) was carried to evaluate the significance of each parameter on the overall weld quality and the adequacy of the developed model. The confirmation tests conducted at optimum levels of parameters proved the effectiveness and robustness of the method.

Application of servqual and servperf methods to assess the quality of teaching services - comparative analysis

Agnieszka Czajkowska, Ingaldi Manuela

Manufacturing Technology 2021, 21(3):294-305 | DOI: 10.21062/mft.2021.041

The features of quality, which is an ambiguous, gradual and very subjective concept, cause that there is no one absolute standard for it. Scientists are looking for ways of its evaluation and improvements of the existing methods. It relates to various areas, but at the same time it is also complex and multi-faceted. There are so many definitions of quality that are constantly evolving. In the paper two meth-ods Servqual and Servperf to assess the quality of teaching services were used. The aim of the paper was to compare the results of the service quality analysis with use of both methods and to indicate the differences between them. It was also checked whether conclusions regarding the quality of ser-vices differ depending on the used research method. The Servqual method takes into account the individual expectations of the respondents, which may affect the assessment of the actual service. It is more complicated, but the results are more adequate to the specifics of the service. It was shown that in one of the areas the results concerning the quality of teaching services differed significantly depending on the used method. However, it is not yet clear which of the two scales is a better meas-ure of service quality.

Comprehensive analysis of the coated component from a FORD engine

Iryna Hren, ©tefan Michna, Jan Novotný, Lenka Michnová

Manufacturing Technology 2021, 21(4):464-470 | DOI: 10.21062/mft.2021.058

The article is devoted to a comprehensive analysis of the coating of a component from the Ford Fo-cus 1.0 l EcoBoost engine. It is one of a pair of materially identical aluminum gears connected by a drive pulley and a drive. Aluminum gear components are surface treated with a mixture of metal powders using PVD technology, where the goal of the coating is to increase the hardness, abrasion resistance and heat of the base material. The chemical composition of the basic material of the gea-red aluminum drive wheel of the FORD engine proves that it is a component made by thermofor-ming and corresponds to the alloy EN AW 6061 (AlMg1SiCu) according to the standard ÈSN EN 573 1-3. The microstructure of the base material component exhibits fine intermetallic phases evenly dis-tributed throughout the cross-section of the base base material, without the occurrence of larger inc-lusions and/or porosity. The cross-sectional microstructure in the area of the coating demonstrates that the component has a continuous uniform surface layer of the coating formed without a defect and does not have a diffuse bond with the base material. The measurement of the coating thickness of the component shows a continuous surface layer formed by powder metallography, which ranges from 70.1 µm to 143.9 µm. The surface EDS of the surface proves that it consists of deposited tungsten carbides produced by powder metallography and the bonding material is cobalt. Area EDS analysis of the surface coating identified morphologically two distinct areas of dark and light, where tungsten carbides and cobalt are based, and only the tungsten carbide and cobalt carbide contents change. The oxygen and carbon content also changes in the dark and light areas.

Kinematic Analysis of the Tram-pedestrian Collision – a Preliminary Case Study.

Lubos Tomsovsky, Petr Kubovy, Frantisek Lopot, Karel Jelen

Manufacturing Technology 2022, 22(1):89-94 | DOI: 10.21062/mft.2022.007

The goal of the study was to conduct a preliminary analysis of the kinematics of tram-pedestrian collision in case of a side impact. A T6A5-type tram, traveling at the speed of 10 km/h, was used for the crash analysis and reconstruction of the collision. The pedestrian response was analyzed using a crash-test dummy. For the purpose of this study, the postimpact dummy movement was approximated by the motion of its center of mass (COM) and only the translation movement in the frontal plane of the dummy (along the horizontal and vertical axes) was considered. The results showed a significant change in the coefficient of restitution after the initial impact. At first, the coefficient of restitution was high (e = 0.94), suggesting an almost perfectly elastic collision, followed by a sharp decrease (e = 0.07) within a short period of time (t = 0.02 s) that suggested an almost perfectly inelastic collision. After that, the coefficient of restitution reached a plateau phase with the values ranging from 0.18 to 0.32 and corresponding to a percentage loss of kinetic energy falling within 89 % and 97 %. The preliminary analysis of this study highlighted some features of side-impact tram-pedestrian collision and its kinematics.

Phase and Mechanical Properties Response of the Mechanically Alloyed CoCrFeNiAlX High Entropy Alloys

Angelina Strakosova, Petr Kratochvíl, Jan Riedl, Filip Prù¹a

Manufacturing Technology 2022, 22(4):471-476 | DOI: 10.21062/mft.2022.059

The present work describes the influence of Al content on the CoCrFeNiAl high-entropy alloys pre-pared by the powder metallurgy technique. The preparation procedure consisted of mechanical alloy-ing and subsequent spark plasma sintering. The content of Al varied from 10 – 30 at.% which affected the microstructure and mechanical properties. Using scanning electron microscope (SEM) and X-ray diffraction analysis (XRD) was found the microstructure becomes more refined with increasing con-tent of Al accompanied by the annihilation of the ductile FCC solid solution (Cr0.25Fe0.25Co0.25Ni0.25) phase and growth of the brittle and hard BCC solid solution phase (α-Fe) and formation of Al(Co0.5Ni0.5) phases, improving the mechanical properties. The best combination of the porosity, hardness HV 30, and ultimate compressive strength (UCS) was achieved for the studied high-entropy alloy when it contained 20 at. % Al.

Flexural and Out-of-Plane Compression Performance of Hexagonal Rubber Wood Core Sandwich with Increasing Cell Wall Thickness

Jennise Tan Teng Teng, Mohd Yuhazri Yaakob, Mohd Amirhafizan Bin Husin, Kamarul Amir Mohamed, Myia Yuzrina, W. Lau

Manufacturing Technology 2022, 22(2):240-253 | DOI: 10.21062/mft.2022.023

This paper investigates the rubber wood honeycomb core by manipulating its cell wall thickness. Rubber wood honeycomb core was fabricated with cell walls range from 1 mm to 3 mm. The impacts of the cell geometrical parameters on the flexural and out-of-plane compression performance are studied. In the case of solid rubber wood without facesheet, the density is much higher than those rubber wood honeycomb composites. The failure can be disastrous without facesheet under bending. Rubber wood honeycomb sandwiches are able to offer the similar specific flexural strength with lower density. With increasing wall thickness from 1 mm to 3 mm, the specific flexural strength increased by 12.32 %. Meanwhile, specific compressive strength improved by 11 % from 1 mm to 2 mm. However, its specific strength dropped by 3.55 % when the wall thickness at 3 mm. Minimum improvement in the compressive strength per density has caused the decrement.

Thermal Stability of Organic Coatings for Aluminium and Its Environmental Aspects

Tatjana Brovdyová, Jiøí Èmelík, Zdeòka Kwoczynski, Jaroslava Svobodová, ©tefan Michna, Tomá¹ Svorník

Manufacturing Technology 2022, 22(4):396-400 | DOI: 10.21062/mft.2022.050

Thermal stability of organic coatings for aluminum plays a key role not only in specific applications, but also in the recycling process of aluminum scrap. For production of secondary aluminum it is necessary to remove coatings from scrap. Rests of unremoved coatings affect the quality of final aluminum. Most of methods for coatings removing are based on thermal decomposition. This process leads to emission of various organic compounds which present potential risk for human health and also for environment. Thermal stability of all tested coatings with in-creasing temperature was study with use of thermogravimetric analysis (TGA). Significant degradation of coating started at temperature 200 °C and at temperature 450 °C was most of the tested coating degraded and remained only inorganic part of coating. Inorganic part render ap-prox. 30 % of the original coating mass. Degradation of tested coatings was also confirmed by Fourier transform infrared spectroscopy (FTIR) analysis. This work also deals with study of in-organic/organic ratio of hybrid coating on real sample of scrap for recycling. The thermolabile part of coating is degraded during heating, which lead to emission of organic compounds and products of degradation which can affect human health and also the environment.

The Diffusion Coatings for Industrial Tool Application

Marcin Drajewicz, Adrianna Przybylo, Jakub Jopek, Marek Góral, Barbara Koscielniak, Kamil Ochal, Tadeusz Kubaszek, Artur Gurak, Kamil Dychton, Mateusz Wozniak, Pawel Kwasniewski, Artur Kawecki, Wojciech Gluchowski, Marek Lagoda

Manufacturing Technology 2022, 22(5):530-541 | DOI: 10.21062/mft.2022.066

The diffusion boriding process allows to increase the abrasion and corrosion resistance of the majority of steel grades. The aim of this study was to determine the influence of the chemical composition of the substrate of various steel grades on the microstructure of boride coatings produced using two diffusion methods: pack cementation boriding using EKABOR-2 and paste-pack boriding using EKABOR-PASTE on the substrate of tool and structural steels:. The boriding processes were carried out at 1000oC in an argon atmosphere for 4h. Scanning microstructure investigations of the obtained coatings indicate that a high content of alloying elements increasing the FeB (Cr, Mo, W) phase, results in the formation of an external, continuous layer of FeB borides. It was found that with increasing alloying element and carbon concentration, the total thickness of the boride coatings decreases. In particular, a chromium content below about 1%, with a carbon content below about 0.4%, significantly limits or prevents the formation of the FeB phase. Increasing the content of alloying elements and carbon, results in a change in the morphology of the iron borides.

Comparison on Milling Force Model Prediction of New Cold Saw Blade Milling Cutter Based on Deep Neural Network and Regression Analysis

Shuailiang Guo, Han Zheng, Xiangzeng Liu, Lizhi Gu

Manufacturing Technology 2021, 21(4):456-463 | DOI: 10.21062/mft.2021.053

A four factors and three levels orthogonal milling force (MF) test is designed, which qualitatively obtains the influence of four factors, namely workpiece material, workpiece diameter, milling speed and feed per tooth, on MF of the new cold saw blade milling cutter (NCSBMC), then further verifies the reliability of test data with simulation analysis of MF. The multiple linear regression analysis and deep neural network (DNN) are used to accurately fit and predict the magnitude of MF in three directions of NCSBMC, taking into account the influence of workpiece material factors on MF. Compared with the results of empirical formula, DNN has higher prediction accuracy. The research results provide theoretical guidance for the optimization of milling parameters in actual machining process.

Modern Technical Solutions for Cleaning, Disinfection and Sterilization

Antonín Svoboda, Milan Chalupa, Josef Jelínek

Manufacturing Technology 2022, 22(6):754-763 | DOI: 10.21062/mft.2022.089

Abstract: The article describes a new technical solution for ensuring efficient and inexpensive cleaning, disinfection and sterilization of production facilities and their equipment, based on the principle of gen-erating the use of ozone gas. It describes the technical solution and construction of sterilization and cleaning equipment with ozone gas and the sterilization of small objects, especially textiles contaminat-ed with various viruses, including the Covid-19 virus. The device is designed as energy-saving, structur-ally simple, with high sterilization and cleaning efficiency. The sterilization device is small in size, mo-bile and its design enables transportation in the trunk of an ordinary passenger car. The weight of the device is 14 kg. The device's ozone source is an ozone air purifier, mass-produced according to valid EU standards. The power source of the ozone purifier is an electrical source with a voltage of only 230 V and a frequency of 50 Hz. Alternatively, it is possible to use power from a safe mobile source or inverter. The operation of sterilization and cleaning device in a closed, non-ventilated area, does not endanger peo-ple's health or damage plants. The description of the construction of a technical sterilization device is focused on a specific type of device, but the stated theoretical results can be equally well used in the electrotechnical, food, medical or pharmaceutical industries and in general wherever there is a need to effectively and efficiently clean and sterilize production objects, their equipment, used materials and all other production aids means and tools.

Simulation of Liquid Flow in Pipe

Blanka Skoèilasová, Jan Skoèilas

Manufacturing Technology 2013, 13(4):542-547 | DOI: 10.21062/ujep/x.2013/a/1213-2489/MT/13/4/542

The paper deals with the mathematic modeling of the liquid turbulent flow in the pipe with circular cross-section. The aim is to compare two methods of solution for various geometries and Reynolds numbers. One of the methods is simulation of the system in the commercial software ANSYS Fluent, the second one is analytical solution for simple geometry by equation usually applied in the common design process. The work arises from the requirement to design the computational model based on the FVM, which enables to simulate the various physical phenomena which appear at liquid flow. The solved problem is quite range and therefore the work is only the first part of the systematic investigation. This basic part is important for the decision of the suitable software tools, turbulent model, etc. The investigation of the heat transfer on the cross flow over the tube placed in the bounded surrounding.

Testing the Effect of Bending Moment on Wheel Bearing Heating

Dana Stancekova, Jozef Mrázik, Miroslava «avodová, Al¾beta Sapietová, Anna Rudawska, Filip Turian

Manufacturing Technology 2022, 22(1):71-79 | DOI: 10.21062/mft.2022.004

Leading manufacturers and sellers of products in the field of rolling bearings for the automotive in-dustry guarantee their quality. Extensive product testing is required to guarantee quality. When test-ing wheel bearings, bending fatigue test stations are used, among other things, to verify the strength of components. The content of the presented work is the analysis of the effect of bending moment on the temperature of a newly wound wheel bearing of the 3rd generation, based on experimental measurements. These are dynamic tests of the strength of wheel bearing components at a resonant test station. This verification is very important and has the effect of preventing the start of mass pro-duction of components that do not meet the basic safety requirements.

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