Manufacturing Technology Journal, 2020 (vol. 20), issue 1
Development of the Manufacturing Geometry of Conical and Cylindrical Worms by Analysing of Their Axoids
Zsuzsanna Balajti
Manufacturing Technology 2020, 20(1):3-10 | DOI: 10.21062/mft.2020.003 
In this paper an examination has been outlined a possibility of further generalization respecting the Dudás?s kinematic-mathematical model, which is suitable for the production geometric development of elements of helicoid drive pairs. The positioning of the rolling surfaces of the cylindrical and conical surfaces, as axoids of worms, in the extended model to the projective space under the right conditions, based on the surfaces invariant to projective transformations can be a right extension of the model, as the projective space model includes the Euclidean space model in full. The machining of the conical worm surfaces modelled in this method involves...
The issue of regeneration of metal powder DLMS 3D printing
Karla Burgerova, Ales Herman
Manufacturing Technology 2020, 20(1):11-17 | DOI: 10.21062/mft.2020.014
The subject of the article is a comparison of new and used powder for 3D metal printing. The powder is 316L stainless steel manufactured by Renishaw. The powder used was taken from the RENISHAW AM250 printer after use. Powder manufacturer Renishaw recommends using 15-45 micron powder in their 3D metal printers. An im-portant parameter of monitoring is the chemical composition of the metal powder and its changes during the thermal treatment during laser sintering. Another important parameter of a metal powder is its mechanical prop-erties, which determine the flowability, consistency and uniformity of powder application. By using an inert at-mosphere...
Grinding of maraging steel 1.2709 with SiC grinding wheels and effect of grinding conditions on the surface roughness and wear of the wheels
Jindřich Farský, Tomáš Bakša, Miroslav Zetek
Manufacturing Technology 2020, 20(1):18-22 | DOI: 10.21062/mft.2020.018
Grinding is one of the basic finishing operations which can be used for parts made from different materials where high quality and surface accuracy is required. One of these materials is maraging steel 1.2709, which is used for the test samples for tensile testing. In this case, it is very important to achieve good surface quality. Wear of a grinding wheel is best expressed as G-ratio which shows us if the grinding parameters are selected correctly. This article deals with the influence of grinding conditions and grinding wheels on surface roughness and wear of the grinding wheels when grinding tool steel VACO 180 on a 5-axis grinding machine. The...
Comparison of lightweight and solid milling cutter capabilities
Pavel Hanzl, Ivana Zetková, Miroslav Zetek
Manufacturing Technology 2020, 20(1):23-26 | DOI: 10.21062/mft.2020.008
Milling is one of the oldest methods of metal machining. This technology has been developed over a long time. The last milestone is the use of composite materials for the construction of cutting tools. However, there are other pos-sibilities for improvement offered by new production methods such as Metal Additive Manufacturing. The paper deals with machining experiments using a lightweight milling cutter with a lattice structure. The results of machin-ing are compared to the capabilities of a solid milling cutter. The evaluated parameters are: cutting forces, blade wear and surface roughness of the workpiece. Based on these parameters, it was not possible...
Cutting Forces, Chips Formation and Surface Roughness in Rock Cutting Using Negative Rake Angle
Yuni Hermawan, Rudy Soenoko, Yudy Surya Irawan, Sofyan Arief Setyabudi
Manufacturing Technology 2020, 20(1):27-35 | DOI: 10.21062/mft.2020.009
This research pertains to rock cutting used negative rake angle. The parameters used are negative rake angles of 0o, -5o, -10o, -15o, -25o, -30o, and -40o. Negative rake angle is known to play an important role in rock machining. Negative rake angle produces more chips powder in front of the tool surface. The interaction between these particles affects the thrust force that suppresses the rock surface. A large thrust force generates hydrostatic pressure around the tooltip. According to the findings of this research, negative rake angle -25o leads to the largest thrust force and smallest surface roughness for 15.17 N and 1.21 ?m, respectively with smooth...
Investigation on Tool Wear Mechanism during dry cutting 304 Stainless Steel
Jianjian Chen, Yufeng Wang, Yan Zhang, Shubao Yang, Xingquan Zhang
Manufacturing Technology 2020, 20(1):36-44 | DOI: 10.21062/mft.2020.011
With the determined parameters of cutting speed, feed rate and back cutting depth, cemented carbide tool was adopted to dry cut 304 stainless steel, exploring the tool wear failure mechanism and its effect on the surface quality of the workpiece under different cutting times. The morphology of the tool surface is observed by scanning electron microscopy, and the component of the tool is analyzed by energy dispersive spectroscopy. The three-dimensional microscopic shape of workpiece surface is observed by a three-dimensional shape analyzer and the surface rough-ness Ra was measured. The results indicate that during the process of 6-minute cutting, the...
Chemical degradation of 3D printed products
Vaclav Kaspar, Jakub Rozlivka
Manufacturing Technology 2020, 20(1):45-48 | DOI: 10.21062/mft.2020.010
This template describes the behavior of products created with additive 3D printing technology. The tested material used to produce the samples was polyactide acid (PLA). PLA is one of the most favourite material for 3D printing. This polylactide acid contains a metal additive. The standard dog-bone shaped samples reinforced with internal ribs arranged in a grid with 20% of the internal volume of the rib-filled sample were tested for tensile strength. The samples were subjected to different types of chemical degradation prior to the test. As a degradation agent, there was used an organic solvents. The result of the research is the effect of the degradation...
Preliminary Quality Control of Magnetic Materials for applications in Restorative Medicine - Quantitative Analysis of Structural Homogeneity of RE-M-B /Polymer Composites
Dorota Klimecka-Tatar, Grażyna Pawłowska, Klaudia Radomska
Manufacturing Technology 2020, 20(1):49-54 | DOI: 10.21062/mft.2020.015
The properties of bonded magnetic materials (RE-M-B /polymer magnetic composites) depend not only on the magnetic properties of powder, but also on the parameters of the consolidation process and the type of binder. Increasing the binder content in RE-M-B /polymer composites could be very beneficial from the cor-rosion resistance point of view, which, unfortunately, is not conducive to the magnetic properties improve-ment. Therefore, a compromise between both trends is necessary to obtain a material with adequate corro-sion resistance with an acceptable decrease in magnetic properties. In the paper the results of research un-der Nd12Fe77Co5B / biotolerant-polymer...
Vertical vibration of the vehicle when crossing over transverse speed bumps
Frantisek Klimenda, Josef Soukup, Blanka Skočilasová, Jan Skočilas
Manufacturing Technology 2020, 20(1):55-59 | DOI: 10.21062/mft.2020.020
The experimental investigation of the vertical vibration of the vehicle is presented. The vibration of the two axles vehicle is excited by crossing of the vehicle over the transverse speed bumps on the road. The methodology is oriented upon the quarter, half and full model solution. The full geometry model is the most suitable model for the vertical vibration of the vehicle. The full geometry model is capable to describe geometric and construction asymmetry of the vehicle. The methodology of an analytical solution of the symmetry and asymmetry distribution of the vehicle and load is presented. Also, symmetric and asymmetric excitation is involved to...
The Effect of Cryogenic Treatment on Mechanical Properties, Wear and Corrosion Resistance of Aluminium Alloy AW7075
Ludmila Kučerová, Jiří Hájek, Jan Vítek
Manufacturing Technology 2020, 20(1):60-65 | DOI: 10.21062/mft.2020.004
Effect of addition of cryogenic treatment to a standard heat treatment of aluminium alloy AW 7075 was tested in this work. Used heat treatment consisted of solution annealing at 470 °C for two hours and precipitation aging treatment at 130°C for 14 hours, 120 °C for 24 hours or natural aging at room temperature for 60 days. One set of samples was processed by solution annealing and aging treatment and the second set of samples incorporated 24 hours long cryogenic treatment at -185 °C between the same solution annealing and aging. Both sets of samples were characterised by tensile testing, notch impact testing, hardness measurement, microstructure analysis...
Finite Element Analysis and Lightweight Design of Hydro Generator Lower Bracket
Yongyi Liao, Baiyu Liao
Manufacturing Technology 2020, 20(1):66-71 | DOI: 10.21062/mft.2020.017
Lower bracket is an important component in hydro generator. Taking lower bracket as the research object, the strength, the stiffness and the dynamic characteristics of lower bracket have been simulated and analyzed by means of establishing a finite element model. With the two design indexes of maximum normal stress and stiffness as the constraint conditions, aiming at an optimized design with the minimum mass and proposed a lightweight optimization method. The design parameters of the optimized model of hydro generator lower bracket are determined by using the compound form method with optimization iteration. Through lightweight optimization design,...
Microstructural analysis of examined 33NiCrMoV15 steel and investigation of its nanome-chanical properties after machining
Jozef Majerík, Igor Barényi, Josef Sedlák, Roman Kusenda, Maroš Eckert
Manufacturing Technology 2020, 20(1):72-77 | DOI: 10.21062/mft.2020.007
The authors presented paper deals with experimental measurement and evaluation of nanomechanical properties of hard turned and grinded surfaces on the cross section specimens made of the 33NiCrMoV15 steel. 33NiCrMoV15 steel was selected to perform for all realized investigations. Even before the start of the experi-ments that investigated the effect of hard finish turning against grinding, it was necessary to subject the investi-gated 33NiCrMoV15 steel to basic research with regard to its chemical composition, fundamental microstructure and basic mechanical properties. The microstructure was performed on Neophot 32 optical microscope. Chemical composition...
Influence of semisolid squeeze casting technology on alpha phase and eutectic of AlSi7Mg0.3
Richard Pastircak, Denis Martinec, Elena Kantorikova
Manufacturing Technology 2020, 20(1):78-83 | DOI: 10.21062/mft.2020.012
The paper deals with processing of material in semisolid state by the technology of semisolid squeeze casting. The investigated material was a subeutectic aluminium alloy AlSi7Mg0.3. The influence of various preparation meth-ods of batch material on the structure after processing by this technology was studied. Alloy AlSi7Mg0.3 was pre-pared as gravity cast, inoculated, heat treated and by technology of direct squeeze casting. In article is assessed microstructure of castings before and after processing by technology of semisolid squeeze casting. The shape and distribution of eutectic silicon was observed. The shape and the distribution of alpha phase...
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...
Influence of Stress State on the Yield Strength of Aluminium Alloy
Jiri Sobotka, Pavel Solfronk, David Korecek
Manufacturing Technology 2020, 20(1):92-97 | DOI: 10.21062/mft.2020.005
The basic mechanical properties of structural materials (e.g. yield strength, ultimate tensile strength, uniform and total ductility, anisotropy coefficient, etc.) represent fundamental material characteristics. These parameters are mostly detected by a static tensile test. From the stress state point of view, it is therefore a uniaxial tension stress state. However, the service load usually means acting of wide range of stress states. For this reason, the department of engineering technology at TUL developed a device enabling loading the sample by planar bi-axial loading with the possibility to change ratio of their loading. It is therefore possible...
Utilization of Advanced Computational Methods to Predict Spring-back of Aluminium Alloys in Automotive Industry
Pavel Solfronk, Jiri Sobotka, David Korecek
Manufacturing Technology 2020, 20(1):98-103 | DOI: 10.21062/mft.2020.006
The automotive industry is one of the most dynamically developing segments of the industrial production worldwide. The introduction of still increasingly stringent emission limits for newly developed cars forces car producers to still reduce the fuel consumption of cars. One option is to use hybrid drive units in combination with a redesign of the automobile body while maintaining the highest possible level of vehicle safety. For these reasons, the automotive industry has been increasingly demanding to apply and process low density (lightweight) alloys, including aluminium-based alloys. These materials are subject to high demands both in terms of mechanical...
Study of Factors Affecting Vibration Damping Properties of Multilayer Composite Structures
Martin Vašina, Lumír Hružík, Adam Bureček
Manufacturing Technology 2020, 20(1):104-109 | DOI: 10.21062/mft.2020.019
At the present time, mechanical vibration is undesirable in many cases. Therefore it is necessary to minimize unwanted vibrations in any appropriate manner. This paper is focused on a study of factors influencing vibration damping properties that were investigated using multilayer composite structures. Frequency dependencies of the displacement transmissibility over a frequency range of 2?1500 Hz were determined by the method of forced oscillations. It was found in this study that the vibration damping properties of investigated multilayer structures are significantly influenced by number of material layers, excitation frequency of mechanical vibration,...
Cores Produced by Geopolymer Binder System Technology and Impact to Casting Quality in Comparison with PUR Cold Box Amin
Michal Vykoukal, Alois Burian, Markéta Přerovská, Milan Luňák, Štefan Kyselka
Manufacturing Technology 2020, 20(1):110-119 | DOI: 10.21062/mft.2020.001
The article deals with geopolymer binder system for core production and comparison with PUR cold box amin technology. A sodium-potassium type of geopolymer binder is the subject of the research. The goal of the article is the core production and observing of technological properties, storing cores, usage of refractory coating evaluating of properties during the pouring and decoring of casting. The main target of the experiment is casting quality. It was stated that the final surfaces are much more better than PUR cold box amin technology and the internal casting quality is the same, it means without inadmissible internal defects. Worse decoring times...
The Thermal and Structural Analysis of Vertical Stability Coil
Xianewei Wang, Peng Han, Qing He, Xiulian Li
Manufacturing Technology 2020, 20(1):120-125 | DOI: 10.21062/mft.2020.002
The vertical stability coil is a new set of saddle shaped non-superconducting coil designed for the purpose of improving the control capability of plasma vertical movement. To avoid the electromagnetic shielding and en-hance the response performance, the vertical stability coil is installed in the inner wall of vacuum vessel. The subsequent disadvantage accompanying the benefit is that the coil is under severe neutron radiation. Besides the neutron radiation the coil will also encounter the ohmic heat once it is energized. The temperature rising of vertical stability coil is not allowed to beyond the specific threshold to guarantee the reliability...
A research on closed-loop control strategy for single-phase off-grid inverter under abrupt load variation
Na Yao, Zhaoyun Zhang, Zhiping Wang
Manufacturing Technology 2020, 20(1):126-132 | DOI: 10.21062/mft.2020.016
This paper proposes a control strategy for single-phase off-grid inverter, which integrates the three closed-loop control with the iterative-based RMS algorithm. The inverter circuit is modeled, and simulation experiment and prototype verification are performed on Matlab. The results show that the voltage drop problem caused by an abrupt variation of inverter load is improved greatly owing to the addition of voltage RMS loop. Meanwhile, the application of iterative method enhances the dynamic response performance of the system substantially; and improves the real-timeliness of three closed-loop control. The two complement each other to provide a highly...