Manufacturing Technology Journal, 2018 (vol. 18), issue 6
The High-Temperature Loading Influence on Orthorhombic Ni3Nb DOa δ - Phase Formation and its Effect on Fatigue Lifetime in Alloy 718
Juraj Belan, Alan Vaško, Lenka Kuchariková, Eva Tillová, Miloš Matvija
Manufacturing Technology 2018, 18(6):875-882 | DOI: 10.21062/ujep/194.2018/a/1213-2489/MT/18/6/875 
The orthorhombic DOa Ni3Nb delta phase is naturally presented in microstructure of cast or wrought Ni - Cr - Fe base alloy 718. It is a reason of chemical composition heterogeneity. For delta phase formation is a minimum Nb content about 8% needed and temperature above 650°C and higher. A typical place, where delta phase is situated are grain boundaries in alloy 718, where its role is discutable. Some references saying about lowering the mechanical properties when delta phase is segregated at grain boundary. To approve or disprove of this fact, the wrought alloy 718 with ASTM 12 grain size was subjected to high-temperature loading at push - pull fatigue...
Analysis of Microstructure Changes for AlSi9Cu3 Alloy Caused by Remelting
Dana Bolibruchová, Marek Matejka
Manufacturing Technology 2018, 18(6):883-888 | DOI: 10.21062/ujep/195.2018/a/1213-2489/MT/18/6/883
The use of recycled or remelted alloys is one of the most common ways to reduce production costs. As the number of remelting increases, also chance of the chemical composition and the microstructure alteration is increasing, which has a major impact on the resulting mechanical properties. The microstructure of recycled alloys mostly affects the presence of iron and its negative effect on casting properties. The paper deals with the degree and the way of influence of the remelting on the microstructure of AlSI9Cu3 alloy with increased iron content to 1.4 wt. %. In the work are progressively evaluated changes of microstructures focused on the morphology...
The Effect of Polymer Pin Ribs on Reinforcement of Sandwich Structures
Ladislav Fojtl, Lukas Manas, Sona Rusnakova
Manufacturing Technology 2018, 18(6):889-894 | DOI: 10.21062/ujep/196.2018/a/1213-2489/MT/18/6/889
This research paper deals with an influence of reinforcing polymer ribs on selected mechanical properties of sandwich structures. Reinforcing epoxy ribs are produced directly by the vacuum infusion technology when resin during its flow fills the prepared holes in the polymer core. In the experiment, two rib sizes (diameters) were tested as well as two variants of hole patterns on the core surface. The possible influence of the core material was evaluated on two core material types with different thicknesses. In addition to the observed mechanical properties observed, the types of failure and changes of the sandwich panels weight were also characterized....
Surface Properties of Powder Injection Moulded Parts Related to Processing Conditions
Berenika Hausnerová, Daniel Sanétrník, Vladimír Pata
Manufacturing Technology 2018, 18(6):895-899 | DOI: 10.21062/ujep/197.2018/a/1213-2489/MT/18/6/895
The surface quality of ceramic items produced via powder injection moulding (PIM) at processing conditions varying in injection moulding temperature and debinding route is investigated. The analysis is performed on aluminium oxide part design containing complicated rotational areas, where a smooth surface of an internal spiral is a critical quality factor. Surface properties of the final sintered parts are examined with the help of a contactless scanner. Then, the obtained surface roughness data are treated with suitable statistical analytical tools in order to reveal the effect of the processing conditions during the PIM process on the final parts....
Fractographic Analysis of Strontium-Modified Al-Si Alloys
Iryna Hren, Jaroslava Svobodova
Manufacturing Technology 2018, 18(6):900-905 | DOI: 10.21062/ujep/198.2018/a/1213-2489/MT/18/6/900
The research described in this contribution is focuses on fractographic analysis of the fracture area of AlSi7Mg0.3 alloy with modified strontium. Modification is an effective tool for improving the mechanical properties of aluminum alloys and affecting the microstructure of the material. The aim of the paper is to revise the microstructure of the modified AlSi7Mg0.3 alloy and to determine its strength properties. Within the experiment, the character of the refraction was evaluated and the presence of foreign particles and elements in the material fracture was monitored. Optical microscopy identified structural parameters of the castings just below...
Using Additives for the Production of Castings from the Gray Cast Iron
Martina Hrubovčáková, Iveta Vasková, Martin Conev
Manufacturing Technology 2018, 18(6):906-911 | DOI: 10.21062/ujep/199.2018/a/1213-2489/MT/18/6/906
The Cold-Box Amine method was developed in 1965 by Ashland. For more than 35 years, this method has been applied worldwide and has become the most important method of cold curing. The veining is characteristic defect of cast iron alloys, which accompanies the use of Cold Box-amine cores, the solution to this defect is the content of this paper. There are many factors that affect the surface of the casting and thus the formation of veining. In recent years, products have appeared on the market - additives to prevent veining. Castings using these products should have a smooth surface, no protrusions and other foundry defects. These products have their...
The Heat Treatment Impact on Material Properties of 34CrNiMo6 Steel
Mariana Janeková, Daniela Koštialiková, Andrej Dubec, Matej Burget, Františka Pešlová
Manufacturing Technology 2018, 18(6):912-916 | DOI: 10.21062/ujep/200.2018/a/1213-2489/MT/18/6/912
An article deals with the assessment of the heat treatment of the material for a particular machine component. This material is 34CrNiMo6, made of two melts. This steel belongs to a group of materials with special properties for working at higher temperatures and for the production of demanding components, turbine wheels, cardan shafts, toothed wheels. The material was evaluated for microstructure quality before and after heat treatment. Based on metallographic microstructures, it is possible to review the heat treatment mode, which subsequently affects the mechanical properties of the components. For a particular design element, better cast material...
The Influence of CH4/N2 Gas Ratio on the Structure and Chemical Composition of Cr(C, N) Coatings Deposited by CAD Technology
Pavel Kejzlar, Totka Bakalova, Nikolay Petkov, Hristo Bahchedzhiev
Manufacturing Technology 2018, 18(6):917-922 | DOI: 10.21062/ujep/201.2018/a/1213-2489/MT/18/6/917
This article presents the study of the influence of the bias voltage and CH4/N2 gas ratio on the structure and chemical composition of Cr(C,N) coatings. The coatings were deposited by cathodic arc evaporation of pure Cr (99.99 %) cathode under an atmosphere of a mixture of CH4 and N2 gasses at the low deposition temperature of 300 ˚C. The ratio of reactive gasses was changed from 0 to 100 %. Energy-dispersive spectroscopy showed a linear dependence of resulting C/N ratio on the process gas ratio. The roughness of layers prepared from a mixture of process gasses is higher compared to pure gasses.
Dust Concentration in Air during the MDF Boards and Polystyrene Milling Operations on CNC Milling Machine
Pavel Kic, Miroslav Müller
Manufacturing Technology 2018, 18(6):923-927 | DOI: 10.21062/ujep/202.2018/a/1213-2489/MT/18/6/923
During the material milling an amount of dust which can significantly influence surroundings is generated. Mainly workers are exposed to a dust pollution. The aim of this paper is to present results of a microclimatic research focused on the dust pollution in a workshop during the milling of MDF boards (Medium Density Fibreboards) and Polystyrene workpieces on CNC milling machine. The concentration of air dust was measured by the DustTRAK II Model 8530 aerosol monitor. Using the special impactors the PM1, PM2.5, PM4, PM10 size fractions were also measured. Obtained results of measurements and concentrations of different size of dust particles were...
The Character of Long-Term Abrasion of Dental Implant
Daniela Koštialiková, Mariana Janeková, Andrej Dubec, Ing. Matej Burget, Františka Pešlová
Manufacturing Technology 2018, 18(6):928-934 | DOI: 10.21062/ujep/203.2018/a/1213-2489/MT/18/6/928
During the period of use, there are in the dental implants, the limit conditions of the primary structure and later on its disruption created. The aim of the work was to study microscopic defects in the proposed materials in which the unwanted defects arose and led to early end of the lifetime. It is a dental implant, which had to be prematurely taken from the oral cavity due to limit conditions of the patient pain.Investigation of chemical elements of dental implant materials has shown the presence of such components, which lead to create undesirable intermediate phases in the structure and therefore the analysis of the implants has been complemented...
Effect of Heat Treatment on the Microstructure of the Alloy AlSi7CrMnCu2.5
Pavel Kraus, Nataša Náprstková, Klára Jirounková, Jaromír Cais, Jaroslava Svobodová
Manufacturing Technology 2018, 18(6):935-942 | DOI: 10.21062/ujep/204.2018/a/1213-2489/MT/18/6/935
The article discusses the effect of heat treatment on the microstructure of the aluminum alloy AlSi7CrMnCu2.5. Heat treatment of aluminum alloys can be defined as a technological process by which products or components in solid state are exposed to one or more annealing cycles in order to achieve the desired structure. Thanks to these structural changes it is possible to affect the mechanical properties by the hardenable alloy. Samples where the research was conducted were cast from AlSi7CrMnCu2.5 alloy produced by gravity casting technology in metal mold. Subsequently, the castings were subjected to a heat treatment. The microstructure changes of...
Hardness Tests and Dimensional and Shape Precision Analysis of Construction and Agricultural Machinery Components
Petra Kvasnová, Martin Kučerka, Dušan Hrubý, Daniel Novák, Viktor Novák
Manufacturing Technology 2018, 18(6):943-949 | DOI: 10.21062/ujep/205.2018/a/1213-2489/MT/18/6/943
The article deals with hardness tests and dimensional and shape precision analysis of construction and agricultural machinery components, namely with the clamping head and case of hydraulic hammer. The clamping head is made of 41 4220 class (1.7131, 16MnCr5) construction stainless steel and the case is made of 41 5130 class (1.7218, 25CrMo4) construction stainless steel. The micro hardness was measured on VICKERS LM 700 AT hardness tester, according to the national standard STN EN ISO 6507-1: this procedure includes injection of a diamond regular four-bladed pyramid with a 136° peak angle into the tested material with following parameters: objective...
The Effect of Different Modifiers on Cutting Temperature in Turning of AlSi7Mg0.3 Alloy
Michal Martinovsky, Jan Madl
Manufacturing Technology 2018, 18(6):950-953 | DOI: 10.21062/ujep/206.2018/a/1213-2489/MT/18/6/950
One of the problems in machining Al alloys represents machinability of these materials. Machinability is a characterised by several characteristics. One of these characteristics is a cutting temperature. This paper is focused on the effect of selected modifiers in AlSi7Mg0.3 alloy on this temperature. Several variants of this material modified by strontium, calcium and antimony are used. All these materials are compared with non-modified alloy. Moulded castings of non-modified alloy and for each modified variant were made. Gravity-die castings into a metal mould with a thermal insulation were used.
Process Online Monitoring on Cold Extrusion of Internal Thread in High-strength Steel
Hong Miao, Xiang Shan, Shanwen Zhang, Yifu Jin, Dunwen Zuo
Manufacturing Technology 2018, 18(6):954-961 | DOI: 10.21062/ujep/207.2018/a/1213-2489/MT/18/6/954
In order to solve the problems of data collection, data storage, artificial neural networks, real-time display of images, real-time monitoring of current status and recurrence of historical data, online monitoring system of cold extrusion of internal thread process is designed by LabVIEW8.5. The time-domain analysis and time-frequency-domain analysis are carried out for the torque signal, temperature signal, vibration signal, acoustic emission signal and transmitted signal. The research shows that: this online monitoring system can forecast processing status accurately, raise real-time alarm to replace or re-install the thread forming tap, accordingly...
Influence of Surface Integrity after Turning on the Consecutive Plasma Nitridation and Barkhausen Noise Emission
Anna Mičietová, Juraj Uríček, Daniel Heim, Mária Čilliková, Miroslav Neslušan
Manufacturing Technology 2018, 18(6):962-966 | DOI: 10.21062/ujep/208.2018/a/1213-2489/MT/18/6/962
This paper deals with non destructive evaluation of components after plasma nitridation via Barkhausen noise techniques. The effect of the different surface state before plasma nitriding is studied via non destructive Barkhausen noise technique as well as the conventional destructive techniques. Turning operation was performed by the use of the inserts of variable flank wear. The results of experiments show that Barkhausen noise emission is a function of tool flank as well as the different regime of heat treatment. The different state of the surface before plasma nitriding results into the different thickness of compound layer. Furthermore, also the...
Experimental Study of the Durability of Cutting Tips Prepared via Powder and Casting Metallurgy
Peter Monka, Katarina Monkova, Libuše Sýkorová, Martin Novak
Manufacturing Technology 2018, 18(6):967-972 | DOI: 10.21062/ujep/209.2018/a/1213-2489/MT/18/6/967
Machining has long been the most used technology in manufacturing processes. On the other hand, new materials are being developed or new ways of preparing them are being developed. One of such materials is High Speed Steel (HSS). The article deals with experimental study of a cutting tool durability prepared via powder and casting metallurgy. Durability of cutting tips produced from HSS Vanadis 30 (SN 41 9830) were tested during the short-term radial tests. Three modifications of the HSS steel were studied, while two types of them were prepared via powder metallurgy and the third one was made via casting metallurgy. The measured values were statistically...
Engineering Design of a Device for Shearing Metal Sheets in a Non-conventional Way
Ján Moravec, Miroslav Blatnický, Ján Dižo
Manufacturing Technology 2018, 18(6):973-979 | DOI: 10.21062/ujep/210.2018/a/1213-2489/MT/18/6/973
This constribution presents the engineering design of the non-conventional shearing device, which uses for the operation the magnetic field. There is a prototype of the device designed and constructed in laboratory conditions. There are presented all relevant and necessary data of this shearing device supported by figures and scheme. The principle of the device operation consists in the fact that a sheet passes through feed rollers into the shearing position, i.e. into the position between two blades. Lower is fixed and the upper is guided in rails and controlled by means of springs. After the material dividing the electric circuit is interrupted and...
Application Possibilities of Low-temperature Repairs by Welding for Creep-resistance Material GX12CrMoVNb9-1
Jaromir Moravec, Iva Novakova, Jiri Sobotka
Manufacturing Technology 2018, 18(6):980-985 | DOI: 10.21062/ujep/211.2018/a/1213-2489/MT/18/6/980
Paper is focused on the area of the energy devices working under the higher temperatures and pressures. It deals with repair of new and operational-loaded components of steam and gas turbines (valve and turbine chamber, transmitters, vane carriers, flap-lockable valve bodies and so on). Generally, there occur different types of defects at production and operating of these parts. Many defects are caused by casting (shrinkage cavities, pores, cracks) and fatigue defects. Eventually, there can occur also production defects. Moreover, most of the defects in the mentioned parts generally take effect not until during the subsequent technological operations....
Evaluation of an Efficient Modulus in the Biopolymer String Tension
Vladimír Pata, Oldřich Šuba, Libuše Sýkorová, Milena Kubišová, Lenka Hýlová, Martina Černeková
Manufacturing Technology 2018, 18(6):986-991 | DOI: 10.21062/ujep/212.2018/a/1213-2489/MT/18/6/986
Application of biopolymer materials is currently a rising trend. However, many problems are often encountered when evaluating and describing their mechanical properties. The present article will describe a procedure for finding a so-called effective modulus of elasticity of a biopolymer material having the shape of a thin string with a diameter of about 100 μm.Subsequently, there are not only problems in the actual evaluation of the tensile test (which will be demonstrated by the assembled 3D model), but also when the sample is sampled, which is decisive for finding an efficient module. The article will deal with the methodology of sample squeezing...
Heat Transfer and Global Energy Balance in a Plate Heat Exchanger
Elena Pivarčiová, Mohammad Emal Qazizada
Manufacturing Technology 2018, 18(6):992-1000 | DOI: 10.21062/ujep/213.2018/a/1213-2489/MT/18/6/992
Heat transfer evaluation in a plate heat exchanger (PHE) is one of the most common issue which is widely used in many engineering processes. The objective of this paper determine to formulate a global energy balance in a PHE and to study the heat losses, firstly focuses to study the heat transfer in countercurrent and parallel flow and to measure the temperature profile and to determine the number of transfer units (NTU) effectiveness of a plate heat exchanger. An addition to calculate the overall heat transfer coefficient using criteria equations, also focused to draw the temperature profile of the heat exchanger for both configurations countercurrent...
Influence of Material Change of a Single-stage Front Gearbox Drive Shaft on Selected Strength Analysis Parameters
Martin Podařil, Ján Majerník
Manufacturing Technology 2018, 18(6):1001-1006 | DOI: 10.21062/ujep/214.2018/a/1213-2489/MT/18/6/1001
Contribution is focused on the analysis of power ratios on a drive shaft of a single-stage front gearbox and comparison of design solution of drive shaft using selected materials suitable for shaft production in terms of minimizing gearbox dimensions with respect to maintaining the transmitted power. The aim of the authors is to achieve the smallest possible dimensions of the gearbox shaft by changing the materials from which it is made.
Influence of Chemical Composition on Layer Properties of Barrel Steels
Zdenek Pokorny, David Dobrocky, Zbynek Studeny
Manufacturing Technology 2018, 18(6):1007-1010 | DOI: 10.21062/ujep/215.2018/a/1213-2489/MT/18/6/1007
This article deals with influence of chemical composition on depth of diffusion layers and porosity of compound layers after gas nitriding process. Experiments are focused on utilizing of gas nitriding processes for surface treatment. Gas nitriding technologies were applied to steels C 35 (sample A1), 34Cr4 (sample A2) and steel 42CrMo4 (sample A4), which were subsequently evaluated by electron microscopy, GDOES and microhardness methods. The measurements showed the influences of chemical composition of alloying elements in core of material after chemical-heat treatment process on depth of diffusion and influence of technology on development of porosity....
Effect of Cutting Modes and Tool Wear on the Microhardness of the Surface Layer after Face Milling of Structural and Stainless Steels
Alexey Popov, Sergei Babak
Manufacturing Technology 2018, 18(6):1011-1014 | DOI: 10.21062/ujep/216.2018/a/1213-2489/MT/18/6/1011
The quality of the surface layer of the parts directly affects the life cycle of these parts within machine components. The required surface quality of parts can be secured when keeping a certain operational sequence. Each operation in this sequence affects the final result due to the so-called technological heredity. This means that after each operation it is necessary to achieve certain properties, such as maximum achievable microhardness of the machined surface and residual compressive stresses. This research aims to study the management of machined surface quality after face milling of structural and stainless steels. The laboratory of the Department...
The Analysis of Accuracy of Machined Surfaces and Surfaces Roughness after 3axis and 5axis Milling
Marek Sadílek, Lukáš Kousal, Nataša Náprstková, Tomáš Szotkowski, Jiří Hajnyš
Manufacturing Technology 2018, 18(6):1015-1022 | DOI: 10.21062/ujep/217.2018/a/1213-2489/MT/18/6/1015
This article concentrates on the assessment of a 3D shape of parts of components. The 3D shape is divided into three distinctive shapes: a spherical canopy, a pyramid, and a concave transition between these shapes. Create these shape surfaces, various strategies of 3axis and 5axis milling are used. These strategies are described and then compared on a model in CAM MasterCAM software. The surface of the component is further measured with a roughness measuring device. The accuracy of the surface of the component is measured using a 3D measurement centre and then compared between surfaces with a different machining strategy. The last criterion for comparing...
Influence of Technological Parameters on Ageing of Aluminium Alloy AW-2024
Jiri Sobotka, Pavel Solfronk, Michaela Kolnerova, David Korecek
Manufacturing Technology 2018, 18(6):1023-1028 | DOI: 10.21062/ujep/218.2018/a/1213-2489/MT/18/6/1023
Right after the ferrous alloys, aluminium alloys represent the most wide spread used constructional materials of these days. The main reason of such utilization rests mainly in their specific weight, availability, good mechanical properties and corrosion resistance. To enhance their mechanical properties is there, at majority of technically used aluminium alloys, applied thermal treatment. Wrought aluminium alloys are generally processed after the solution annealing and before their natural or artificial hardening. However, in light of the formability is the own ageing process quite undesirable due to strong decrease of the material formability properties....
The Effect of Chromium Addition and Heat Treatment on Phase Composition of Cast FeAlSi Alloys
Martin Švec, Věra Vodičková, Vojtěch Keller, Pavel Hanus
Manufacturing Technology 2018, 18(6):1029-1033 | DOI: 10.21062/ujep/219.2018/a/1213-2489/MT/18/6/1029
A structural studies have been performed on Fe-Al-Si iron aluminides with or without addition of chromium prepared by standard cast process. The effect of chromium addition and subsequent annealing on the phase composition was studied. Very fine precipitates were observed on the grain boundaries in the alloy without chromium addition. On the other hand, complex chromium carbides formed in the structure of chromium doped alloy. The annealing of alloy without Cr addition leads to partial dissolution of secondary phase particles. Unlike the chromium-doped alloy, where the secondary phase coarsed during the annealing process.The phase composition of...
Effect of Al5FeSi Phases in Secondary AlZn10Si8Mg Cast Alloys on Mechanical Properties and Fracture Surface
Eva Tillová, Mária Chalupová, Denisa Závodská, Lenka Kuchariková, Juraj Belan, Alan Vaško
Manufacturing Technology 2018, 18(6):1034-1040 | DOI: 10.21062/ujep/220.2018/a/1213-2489/MT/18/6/1034
Effect of brittle plate-like Al5FeSi iron phases in secondary (scrap-based - recycled) AlZn10Si8Mg cast alloys with different amount of iron (0.150 wt. % and 0.559 wt. %) on microstructure, mechanical properties (UTS, YTS, ductility and Brinell hardness) and fracture surface were studied. Standard, colour and deep etching were utilized for observation and identification of intermetallic phases (in order to reveal the 3D-morphology of the Si-particles and intermetallic phases). X-ray analysis was used for the evaluation of element composition of the specimen. The results show that SDAS factor decreases with increasing the Fe content; the area proportion...
Towards the Prediction of Micro-EDM Drilling Performance on WC Varying the Hole Depth
Gianluca D'Urso, Mariangela Quarto, Giuseppe Pellegrini, Chiara Ravasio
Manufacturing Technology 2018, 18(6):1041-1047 | DOI: 10.21062/ujep/221.2018/a/1213-2489/MT/18/6/1041
The present work deals with the execution of through micro-holes on tungsten carbide plates using a micro-EDM (Electrical Discharge Machining) machine. The investigation focuses on the monitoring of the performance during the drilling phase in order to obtain the in progress behavior of the performance indexes. The experiments were carried out by varying some process parameters such as peak current, voltage and frequency to achieve both high and low power discharge conditions. Regarding electrodes, the most commonly industrial used ones were selected: tubular tungsten carbide and brass. The performance indexes taken into account were machining time,...
Effect of Copper and Molybdenum on Microstructure and Fatigue Properties of Nodular Cast Irons
Alan Vaško, Juraj Belan, Eva Tillová
Manufacturing Technology 2018, 18(6):1048-1052 | DOI: 10.21062/ujep/222.2018/a/1213-2489/MT/18/6/1048
The aim of this paper is to compare the microstructure, mechanical and fatigue properties of three types of the nodular cast irons - unalloyed nodular cast iron, nodular cast iron alloyed by Si and Mo and nodular cast iron alloyed by Si and Cu. For all the types, microstructure, mechanical properties and fatigue properties were investigated. Microstructure of the specimens was evaluated according to STN EN ISO 945 and by automatic image analysis. The image analysis system NIS Elements, interfaced with the light microscope, was used for the evaluation of the shape factor, equivalent diameter of graphite, count of graphitic nodules and content of ferrite....
A Roundness Machine Measuring Probe Calibration
Jiri Vit, Martin Novak
Manufacturing Technology 2018, 18(6):1053-1059 | DOI: 10.21062/ujep/223.2018/a/1213-2489/MT/18/6/1053
The article deals with the research of the measuring probe signal of roundness machine Roundscan of Jenoptik IM producer. The probe of this machine scans geometric form as well as surface structure. The probe signal dependence on the probe arm elevation is not perfect linear and this influences the precision of evaluated form characteristics, roughness parameters as well as drall parameters. A quantification of calibration way influence on the signal characteristic was main research task. A calibration process simulator was designed and built in MATLAB for this. This article describes a way of obtaining of real probe signal. Metrological filters according...