Manufacturing Technology Journal, 2012 (vol. 12), issue 2
The use of magnetic and ultrasonic structuroscopy for inspection of ADI/AGI castings
Zuzana Andršová, Břetislav Skrbek
Manufacturing Technology 2012, 12(2):93-97 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/93 
The Austempered Ductile Iron (ADI) and Austempered Grey Iron (AGI) represent the most progressive group of grafitic irons with reference to mechanical properties. These properties depend on accurate observance of default structure, chemical composition and isothermal hardening conditions. ADI/AGI castings are mostly used in automotive industry for moving parts and safety critical items. The production of ADI/AGI in the Czech Republic is insufficient, even if the automotive is the important member of our industrial production. The NDT can be used as the tool of 100% inspection - that provides constant production quality and could support the production...
Decomposition of form surfaces for planning of machining
Jozef Beňo, Jozef Stahovec, Peter Ižol, Miroslav Tomáš
Manufacturing Technology 2012, 12(2):97-102 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/97
Paper deals with manufacturability of form surfaces produced by 3D milling operations. Based on decomposition of form surfaces, which are designed by CAD, virtual elementary operations of milling form surfaces are presented. Some typical engineering components with form surfaces were designed to analyse their features. Forms surfaces are classified to give review of dimensionless basic shapes. Review of milling strategies is introduced to select planning of machining of surfaces taken from virtual components. A representative component was analysed in order to obtain overall length of tool paths related to the elementary surfaces. Examples of process...
Effect of the processing materials on the ploughing force values
Andrey Dugin, Alexey Popov
Manufacturing Technology 2012, 12(2):102-105 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/102
In micro cutting it is necessary to control the cutting tool. Monitoring of cutting tools is usually accomplished by measuring cutting forces. In order to improve the accuracy of monitoring it is required to consider the ploughing forces. The ploughing forces substantially depend on the processing materials. This article describes the investigation of the effect of processing materials on the ploughing force values. The extrapolation method on zero cut chip thickness was used to determine the ploughing forces. The experiments were performed by cutting of aluminum alloys, structural steels, bronzes and stainless steels.
Experimental verification of the frequency spectrum of unwears and wears guidance tube on the technological head vibrations creation in the production system with AWJ technology
Stanislav Fabian, Štefánia Salokyová, Patrik Jacko
Manufacturing Technology 2012, 12(2):105-108 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/105
The solution and evaluation of the production system (PS) operation with water jet technology was addressed in more works. It is appropriate to complement this knowledge from works focused on investigation of the other factors effect which affecting the emergence and spread of technological head vibrations, affecting reliability, durability, economic efficiency and operation safe of PS with water jet technology. The article presents experimental investigation results of the vibration acceleration frequency spectrums during cutting steel by unwear and wear rectifying tube with water jet technology. The vibrations size was assessed by two basic vibrations...
Temperature stability of the process of production of wax patterns for investment casting technology model
Aleš Herman, Marek Česal
Manufacturing Technology 2012, 12(2):108-112 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/108
In this paper, we deal with the topic of production of precise wax patterns for investment casting technology. We focus on the issue of scanning thermal image arrays when measured object (wax blade model) has a temperature very close to ambient temperature. It is shown on specific examples how to filter disruptive thermal reflections that enter thermal array scanning on almost perfectly reflexive body. Based on verification of this measurement using the touch probe thermometer, this paper deals with the thermal influence of wax models in various stages of production. The biggest influence on stability of wax models occurred on workplace that carries...
Gas Metal Rapid Arc Welding Potential
Zdeněk Hudec
Manufacturing Technology 2012, 12(2):113-118 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/113
The article presents problems with commercial inverter source Rapid Arc application on fillet and V-grooved welds. Principal and conditions of the process are explained and especially restriction due to source and feeder upper power limit is described. Case study of "weld design for fabrication" method was demonstrated, where type of weld and shape of groove is designed on the base of experimental results of process penetration behavior at 1/2 V-groove joint. Results are described and discussed, using special welding parameters monitoring equipment and software. A change of metal transfer behavior was recorded in accordance with torch angle setting...
A Study of the Mechanical Properties of Thermally Treated Recycled Glass Media Used in Vibratory Mass Finishing
Mikdam Jamal, Mike Morgan
Manufacturing Technology 2012, 12(2):119-124 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/119
This paper reports on the outcomes of a study concerned with the mechanical properties of a new abrasive tool manufactured wholly from thermally treated recycled glass. These properties will aid in understanding the behaviour and performance of the treated glass. Mechanical properties were investigated using the most current and advanced nano-indentation methods. A computer controlled Nano Indentation hardness test (NHT) machine was used to obtain values of hardness and elastic modulus. The nano-indentation process was equipped as a FEM parametric model. The model was then processed by purposely developed numerical objective optimization algorithms...
Analysis of welded joint of band-saw blade - influence of annealing process on joint microstructure and mechanical properties
Daniela Kalincová
Manufacturing Technology 2012, 12(2):125-131 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/125
The paper is aimed at the analysis of a welded band-saw blade joint. The analysis is focused on the influence of joint annealing on the microstructure and mechanical properties. The results of experimental work are focused on an assessment of a set of band-saw blades samples made of material DIN C75. The samples have been welded and evaluated in the states prior and after welding and annealing. The purpose of the experiment was to analyse the influence of different annealing temperatures on structural and mechanical properties and based on the analysis to propose optimal heating temperature that guarantees reliable operation of the band-saw blades....
Structure and mechanical properties of Fe-25Al-5Zr and Fe-30Al-5Zr intermetallic alloys
Pavel Kejzlar
Manufacturing Technology 2012, 12(2):131-135 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/131
Iron aluminides are seen as promising candidates for high temperature structural materials to replace expensive nickel-chromium-based stainless steel. Due to their long-distance-ordered structure they exhibit some advantageous properties as an excellent corrosion resistance, low density, high specific stiffness and low raw material cost. On the other hand, they are inherently brittle at ambient temperatures and have insufficient high temperature strength and creep resistance. It has been shown that addition of Zr into Fe-Al-based material leads to precipitation hard ternary intermetallic phases which may enhance high temperature strength. Addition...
The effect of chlorhexidine on the colour and tint change of ceramic dental veneer
Dorota Klimecka-Tatar, Stanisław Borkowski
Manufacturing Technology 2012, 12(2):136-140 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/136
Frequent consumption of certain products contained the different kinds of chemical compounds affects on the colour of teeth, especially on prosthetic restoration timbre. A very interesting issue is to determine the effect of exposure in some of the commonly used chemical substances on dental restorations colour change. The study was conducted on the upper crown of the tooth, namely the first incisor. The colour evaluation change has been made using a spectrophotometer SpectroShade, which determines the amount of light absorbed by the element over the entire visible spectrum 380 - 720 nm. In the paper was shown that long-term use of products that contain...
Diagnosis and damage of bearings
Marek Krynke, Jacek Selejdak, Stanisław Borkowski
Manufacturing Technology 2012, 12(2):140-144 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/140
The article describes typical damage of rolling bearings and basic methods of their detection. From various methods of working bearings diagnosis the vibration method selected. Vibration signal contains a series of important technical information about the machine condition and is currently the most frequently used in diagnostic bearings systems. Furthermore, structure of vibroacoustic signal the frequency generated by the damaged bearing depends on the causes of the damage, the phases of its development and in particular the size of signals from other kinematic nodes, load, service quality and environmental impact. Monitoring the dynamic state of...
The effect of the borehole diameter on the machining times in hard machining
János Kundrák, K. Gyáni, I. Deszpoth
Manufacturing Technology 2012, 12(2):144-150 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/144
When selecting the optional parameters in machining inner cylindrical surfaces the diameter of a borehole cannot be ignored. Also in finish precision machining, when fulfilling strict accuracy and surface quality parameters economically, it was presumed that the size of the borehole diameter has got an effect on the machining times of different procedures. Five different hard machining methods are compared here on the basis of time consumption. The common characteristic feature of the comparative investigations of different hard machining procedures is that their benchmark is always the traditional grinding. This time, too, that has been chosen. It...
Microscopic Evaluation of Protective Coating by Coated Sheets after Corrosion Load
Sylvia Kuśmierczak, Jaroslava Svobodová
Manufacturing Technology 2012, 12(2):151-157 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/151
Introduction into problems - The aim of the paper was microscopically analyze protective layer by coated sheets after corrosion loading which were pre-treated by various ways. The samples were divided into 4 groups according to the pretreatment type and duration of corrosion load. After a corrosive effect on the corrosion chamber the protective layer was subjected to microscopic evaluation. For samples of group I and IV have to degrade the protective layer and the formation of corrosion products on the base material which causes degradation of the protective layer and shorten its life. For samples of group II and III microstructural analysis showed...
Surface Properties in Precise and Hard Machining
Jan Madl
Manufacturing Technology 2012, 12(2):158-166 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/158
Precision machining and especially hard machining is a topic of high interest at present. Surface integrity requirements increase. Hard precision machining may substitute some abrasive operations. There are some advantages of hard cutting over the abrasive machining. Abrasive machining has traditionally performed the finishing process of hardened steel. But, the availability of hard and super hard cutting tools enable the machine tools to reach surface quality of hard machining like to those obtained in grinding processes. A surface is not only a geometric entity but also a layer with its own structure and properties. These properties are affected...
Structure of rapidly solidified aluminium alloys
Alena Michalcová, Dalibor Vojtěch
Manufacturing Technology 2012, 12(2):166-169 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/166
Rapidly solidified alloys are very promising structural materials. When prepared by melt spinning technique in form of thin ribbons, these materials exhibit structural gradient. On the cross section of the ribbon can be clearly distinguished two areas: the ultra rapidly solidified area on the wheel side of the ribbon and the free side of the ribbon. In this article, the microstructure of AlCr3Fe3Ce1 and AlFe6Ce1 rapidly solidified alloys is described. The possibilities of observing of the wheel side and free side areas by transmission electron microscopy are discussed. The classical way of TEM samples from metals - electropolishing is compared to the...
Possible ways of obtaining an aluminium alloy by non-traditional waste processing of aluminium beverage containers
Štefan Michna, Petr Majrich
Manufacturing Technology 2012, 12(2):169-174 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/169
The aim of this experiment was to melt down aluminium beverage containers and making use of the recycling process to acquire an aluminium material of a certain chemical composition for another production process with the aim of manufacturing aluminium semi-products and products. The aluminium material extracted in this way was subsequently analysed chemically and metallographically. These experiments were carried out within three casts and in all three cases the batch was formed by 100% of aluminium scrap in the form of finely shredded aluminium cans (Fig.1) and from the point of view of the complex efficiency assessment of the recycling process a...
The use of fractography in the analysis of cracking after formed workpiece blank mechanical machining from the AlCuSnBi alloy
Štefan Michna, Nataša Náprstková
Manufacturing Technology 2012, 12(2):174-178 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/174
The aim of the performed works was research on the causes of formed aluminum blanks cracking in the range of the AlCuSnBi alloy rods where cracks appear during mechanical machining (turning, drilling) of this range to the final part. AlCuSnBi alloy was invented as a substitute for aluminum machining alloys Al - Cu type alloyed with lead. For the alloy were performed qualitative and quantitative fractographic analysis of the fracture surface after machining in order to determine possible causes cracking of the material and thus his lack of strength during machining. Part of this paper is to the overall theoretical analysis of the issue. This paper clearly...
Cutting ceramic by turning of nickel alloy Inconel
Ivan Mrkvica, Miroslav Neslušan, Ryszard Konderla, Miroslav Janoš
Manufacturing Technology 2012, 12(2):178-186 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/178
This article deals with dry turning of nickel superalloy - Inconel 718. The different ceramic inserts were applied for cutting process. These inserts were produced by Greenleaf Corporation company. This paper discusses durability of cutting inserts, the different intensity of tool wear at various cutting parameters. The most suitable cutting conditions are chosen in the scope of applied tools.
Technology of Perspective Scanning Methods for Realization of 3D Models of Manufacturing Devices
Jozef Novak-Marcincin, Jozef Torok, Jozef Barna, Ludmila Novakova-Marcincinova
Manufacturing Technology 2012, 12(2):186-191 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/186
This article provides perspective into creation of virtual 3D models of manufacturing devices and optimization of existing machine tools by using an alternative scanning device and freeware software applications (open source elements). This alternative offers scans of components surfaces that are from the viewpoint of precision and quality comparable with much more expensive devices. Various parts of the paper describe the process of creation of the environment with the use of Kinect scanner device and various software tools. At the end an additional options are provided for using with sensing device.
G-Ratio in hardened steel grinding with different coolants
Martin Novak, Roman Dolezal
Manufacturing Technology 2012, 12(2):192-197 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/192
This article deals with grinding of the hardened and tempered steel in different coolants. The G-ratio is one of the important parameters of grinding process and shows efficiency of this. The development of machining technologies is still moving forward, there are new materials and types of tool using in production and manufacturing. With a new materials usage we want better parameters of process, e. g. higher G-ratio, lower heat balance and better surface quality after machining. New types of abrasive grains that we used are based on Al2O3 - microcrystalline corundum and parameter of G-ratio and surface quality after grinding will be described in...
Possibilities of the observation of chemical reactions during the preparation of intermetallics by reactive sintering
Pavel Novák, Alena Michalcová, Ivo Marek, Milena Voděrová, Dalibor Vojtěch
Manufacturing Technology 2012, 12(2):197-201 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/197
During reactive sintering production of intermetallic compounds, the thermally-activated reactions usually proceed very rapidly. Therefore the description of the reaction mechanisms is a challenge for current scientists. This work presents four approaches, how to succeed in this task. Thermal analysis, reaction front quenching method, in situ diffraction analysis and process modelling are described.
Microstructure Analysis of Titanium Alloys after Deformation by means of Asymmetric Incremental Sheet Forming
Lucie Novakova, Petr Homola, Vaclav Kafka
Manufacturing Technology 2012, 12(2):201-206 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/201
The contribution describes metallographic analyses assessment of titanium materials - a commercial purity titanium (Grade 2) and Ti-15V-3Cr-3Sn-3Al titanium alloy - after asymmetric incremental sheet forming (AISF) processing. Microstructure pattern and deformation mechanism of the titanium materials are given by the content ratio of α and β phases that define formability of the resulting material. For the sake of description of the deformed parts from the view of mechanical properties, the microhardness measurements were performed on the samples taken from various zones of the resulting complex shape after the AISF processing. A distribution...
Model of chip formation during turning in the presence of a built-up edge (BUE)
Zoltán Pálmai
Manufacturing Technology 2012, 12(2):207-212 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/207
During turning, in the course of the deformation of the material, a metallic deposit, a so-called built-up edge (BUE), may occasionally form, which may damage the surface and shorten the tool life. We have observed the effect thereof on chip formation using microscopic techniques and have developed a mathematical model for this process. Laboratory experience confirms the numeric solution of the time-delayed autonomous differential equations. This model can be applied to other technologies as well where the thickness of the undeformed chip varies.
TEM Investigation of Precipitation in Al-Mn Alloys with Addition of Zr
Michaela Poková, Miroslav Cieslar, Jacques Lacaze
Manufacturing Technology 2012, 12(2):212-217 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/212
Aluminium and its alloys belong to the most widely used metallic materials for industrial applications. One of the possible casting methods is twin-roll casting which produces sheets with high solid solution supersaturation. Decomposition of this supersaturated material during heat treatment was studied in aluminium alloys from the AW-3003 series - one standard grade and the other modified by addition of zirconium. Characterization by differential thermal analysis and observations by electron microscopy revealed that precipitation of α-AlMnFeSi phase occurred in two steps around 360 and 450 °C in twin-roll cast sheets, firstly on subgrain boundaries...
Fatigue resistance of dual phase steels in presence of microstructural inhomogeneities
Gejza Rosenberg, Ľuboš Juhár
Manufacturing Technology 2012, 12(2):217-221 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/217
In the work, there are noted experimental results aimed at determination of influence of initial microstructure of the steel S355, that was exposed to different temperatures of intercritical annealing, on its resistance against cyclic loading by number of cycles needed to fracture the samples, loaded by stress amplitude σa = 500 MPa. Intercritical annealing at temperature ranging 740-840°C was carried out on a bar with the same thickness as the steel sheet in received state (B=9mm). Fatigue tests were realized on 1,2mm thick specimen cut from subsurface and middle area of initial thickness of the plate, where a banding structure occurred, thickness...
Influence of microstructural heterogeneities on capacity to absorb energy of dual-phase steels
Gejza Rosenberg, Iveta Sinaiová, Ľuboš Juhár
Manufacturing Technology 2012, 12(2):222-227 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/222
The effect of microstructural banding (or so called segregation bands) on energy absorption capacity of dual-phase steels (DP steels) was examined by product of tensile strength and uniform elongation (TS×UE), as well as by Charpy V-notch impact test. A series of DP steels with different volume fractions of martensite (VFM) was prepared by intercritical annealing at temperatures ranging 740 to 840 °C. It was found that increasing of VFM has an inverse effect on values TS×UE and notch toughness. The results on samples with a notch and pre-cycled crack showed that presence of segregation bands influences capacity of steels to absorb the energy in initial...
The importance of measured values number in evaluating the wear size of inserts
Ludek Ruzicka, Jan Madl
Manufacturing Technology 2012, 12(2):227-232 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/227
In evaluating larger number of measurement data, it is proper to analyze them statistically. It is important to determine the effect of measured data number on the experiment results. This paper is focused on the determination of the effect of the basic file size (data obtained in the experiment) on the final measurement results. In milling the cutting inserts of sintered carbide (SC) were used. The same cutting conditions (depth of cut, feed, cutting speed) and were used. The cutting inserts wear was measured after the same cutting time. At the beginning of experiment 120 measured data (edges) were used. Number of measured data was gradually increased...
Gear-Shaper Cutter with Curvilinear Side Flank Face
Roman Siecla, Stanislaw Legutko
Manufacturing Technology 2012, 12(2):233-237 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/233
The paper presents a concept of the design of gear shaper cutters with curvilinear side flank faces. The problem of forming the outline of the cutting edge of the gear shaper wedge has been discussed and the possibilities of execution of this type of knives have been indicated. The method of forming the rake face of curvilinear side flank face has been presented.
The Roundness and Microstructure of Thin-wall Bearing Rings
Augustín Sládek, Peter Fabian, Richard Pastirčák, Martin Brezničan
Manufacturing Technology 2012, 12(2):237-241 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/237
Heat treatment of rolling bearings components is an indispensable part of their production and also is the unavoidable item of the price in calculating of bearings. Technological process of heat treatment must be created rationally and in addition to the required hardness must also ensure the dimensional precision of bearings components. For predicting of the development of thermal and mechanical properties during heat treatment (for simulation only quenching) we used the simulation software SYSWELD from ESI Group. In addition to the microstructure and hardness the simulation results also consist of values of deformations and stresses in each axis...
Value engineering as the way of quality problems solving in the steel construction management
Renata Stasiak-Betlejewska
Manufacturing Technology 2012, 12(2):242-247 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/242
The study aim was discussion on the steel construction production with regard to quality problems and its analysis by using value engineering. The most important elements of the work should, however, discuss how an important factor for the company's production and quality management are. Based on this explicit purpose developed the following hypothesis: identification of the nonconformities location in the production process of steel constructions and its causes contributes to the production improvement. The research result is identification of nonconformities formation areas and presentation of the production process improvement methodology by applying...
The Identification of the structures new type Al-Si-Mg Ca alloys with different Ca content using of the color metallography
Elena Střihavková, Viktorie Weiss
Manufacturing Technology 2012, 12(2):248-251 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/248
This paper presents some analysis of color metallography in the identification new structures of aluminium alloys. For experimental purposes aluminium alloy from the group hypereutectic AlSi7Mg 0,3 silumins was used. Alloy and modified using calcium in the form of master alloy AlCa10. The master alloy AlCa10 in the analyzed alloys added to improve the technological properties af alumium alloys, especially fluidity and machinability while maintaining sufficient corrosion resistance of the alloy. The analysis and evaluation of individual structural components are used method of color etching. The analyzed alloy was also subjected to the method of the...
Stress Analysis of Injection - moulded Cylindrical Parts Reinforced with Short Fibres
Oldrich Suba, Libuse Sykorova, Imrich Lukovics
Manufacturing Technology 2012, 12(2):251-254 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/251
An investigation was carried out through a study of the influence of material anisotropy and geometrical parameters of the cylindrical plastic parts reinforced by short fibres, on the state of stress. It has been shown that the result of such injection-moulded processes is an anisotropic product, whose mechanical behaviour differs considerably for that of classical types of isotropic solids. Unlike unreinforced plastics, fibre composites exhibit different stress phenomena and mechanical properties notably in cases where composite parts are highly curved. These unusual effects of their mechanical properties thus need to be considered carefully in the...
The effect of heat treatment on the structure of Nb and C doped Fe3Al iron aluminides
Martin Švec, Věra Vodičková, Pavel Hanus
Manufacturing Technology 2012, 12(2):254-259 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/254
The alloyed iron aluminides with Fe3Al matrix are used as structural materials. Nb, Zr, Ta additives in combination with carbon appear like promising for high-temperature applications [1, 2]. The carbon addition leads to the formation of carbides (NbC, ZrC, TaC) in the structure of the alloy [2, 3]. The presence of this phase in an appropriate shape could enhance high-temperature mechanical properties of aluminides. The effect of the Nb and C addition and the effect of the heat treatment on the phase composition of this alloy were studied [4, 5]. The alloys investigated in this work were annealed at 1000°C/1h and 1150°C/1h in the air. The phase composition...
Investigation of the non-uniform temperature distribution on the metallic charge length during round bars rolling process
Piotr Sygut, Konrad Laber, Stanisław Borkowski
Manufacturing Technology 2012, 12(2):260-263 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/260
Metallic charge heating before rolling process is very important stage of technological process of bars rolling in continuous rolling mills. Achieve of requires metallic charge temperature and permissible temperature difference on its length depends on metallic charge heating method and using of heating furnace. Main reason of form a big temperature differences on the metallic charge length in case of walking beam furnaces is disturbance their correctly work through seal wear between constant and moving elements of furnace hearth. The paper presents results of experimental investigation the non-uniform temperature distribution on the metallic charge...
Microscopical Evaluation of Hard Zinc Refining by Aluminium
Jarmila Trpčevská, Blanka Hoľková, Jana Pirošková, Mária Ferencová
Manufacturing Technology 2012, 12(2):264-267 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/264
Hot-dip galvanizing is one of the most widely used method for protecting of structural steels against corrosion. In general galvanizing process dross called as "hard zinc" is formed on the bottom of the zinc bath. It is formed by the reactions between molten zinc and iron particles in the galvanizing kettle. Hard zinc represents valuable secondary raw material because of the high content of metallic zinc (94-97%). Bottom dross, being an alloy of zinc and intermetallic phase crystals containing 3-6% wt. Fe, has no direct use in the galvanizing process. For this reason there are attempts to elaborate the technology of obtaining a refined zinc containing...
Influence of bonded abrasive particles size on wear of polymeric particle composites based on waste
Petr Valášek, Miroslav Müller
Manufacturing Technology 2012, 12(2):268-272 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/268
Experiments described in this paper determine two body abrasion of two- and three-phase polymeric particle composites with a different size of filler particles. An epoxy resin was the matrix of composite systems, corundum and chips of iron metals represented the filler created from secondary raw materials. The results show clear influencing of composite hardness and abrasive wear resistance caused by the fillers. The influence of the size of bonded abrasive particles on the wear of the composites based on the waste was proved and it is noticeable - with tested abrasive clothes it is 65 times.
Polymeric particle composites with filler saturated matrix
Petr Valášek, Miroslav Müller
Manufacturing Technology 2012, 12(2):272-276 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/272
Composites are materials which combine properties of two and more phases and create entirely new material. In case of the polymeric particle composites one phase - a matrix is represented by the polymeric material most often in a form of an epoxy resin and the second phase - a filler is composed of inorganic particles. The paper deals with the polymeric particle composites whose matrix is composed of the epoxy and polyester resin with a high concentration of a waste corundum (Al2O3) particles. The paper focuses on chosen mechanical qualities of these materials: an abrasive wear resistance and an impact strength. Increased portion of the filler in the...
Effective examination for obtaining relation T=f(vc)
Karol Vasilko
Manufacturing Technology 2012, 12(2):277-281 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/277
In the development of new cutting materials as well as the application of recent ones it is necessary to know the dependence of their durability on cutting speed. Cutting speed, which determines maximum tool durability, can be derived from it. Recent methodology of finding out this dependence is based mainly on long-term machining examinations and tests, which are demanding on time and material and they can be realised only in laboratory conditions. The paper presents a suggestion of short-term, but equally precise examination, which is based on the observation of tool wear depending on cutting speed.
Phenomenon of twist drill
Karol Vasilko, Vladimír Simkulet
Manufacturing Technology 2012, 12(2):281-285 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/281
In 1770 an Englishman, P. Cooke, had a twist drill patented, a tool, which has such specifications at its application, that are not typical for other tools, in spite of its defined geometric shape. During drilling it behaves like a helical spring, it turns as a result of cutting resistance after first turn and it tries to screw off and screw in, which leads to the occurence of torsional vibration. Cutting speed changes considerably along the cutting edge of the drill, by which the coefficient of friction with drilled material and cutting wedge wear change as well. A built-up edge on the face area occures on certain section of cutting edge and it tears...
Structural, mechanical and in vitro corrosion characterization of as-cast magnesium based alloys for temporary biodegradable medical implants
Dalibor Vojtěch, Jiří Kubásek, Milena Voděrová
Manufacturing Technology 2012, 12(2):285-292 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/285
Magnesium based alloys are light-weight materials having a good strength to weight ratio making them of interest for many structural applications in automotive and aerospace industry. Besides, magnesium is also considered as promising metal for construction of temporary biodegradable medical implants like stents or fixation devices for fractured bones. A biodegradable implant progressively corrodes in the human body fluids and is replaced by the healing tissue. No second surgery is needed to remove the implant after the bone has healed. The advantage of magnesium is that it is relatively non-toxic metal and that its mechanical characteristics (strength,...
Study of nano-crystalline metals prepared by selective chemical leaching
Dalibor Vojtěch, Alena Michalcová, Vítězslav Knotek, Ivo Marek
Manufacturing Technology 2012, 12(2):292-296 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/292
Nano-crystalline metals with structural constituents smaller than 100 nm are prospective materials due to very high hardness and strength, high specific surface, chemical catalytic activity, high gas absorption capability and other characteristics. They can be produced by various methods like precipitation from liquids, vapor deposition techniques, intensive plastic deformation, rapid solidification etc. These methods enable obtaining materials of a wide range of crystallite size. The selective leaching of appropriate alloys is another method to prepare nano-crystalline metallic powders (Fe, Co, Cu, Ni etc.) with high specific surfaces. So far, these...
Influence of the homogenization annealing on microstructure and mechanical properties of AlZn5,5Mg2,5Cu1,5 alloy
Viktorie Weiss, Elena Strihavkova
Manufacturing Technology 2012, 12(2):297-302 | DOI: 10.21062/ujep/x.2012/a/1213-2489/MT/12/2/297
In the course of homogenizing annealing of aluminium alloys being cast continually or semi-continually it appears that chemical in homogeneity takes off within separate dendritic cells (crystal segregation). It is about a diffusional process that takes place at the temperature which approaches the liquid temperature of the material. In that process the transition of soluble intermetallic compounds and eutectic to solid solution occurs and it suppresses crystal segregation significantly. Temperature, homogenization time, the size of dendritic cells and diffusion length influence homogenizing process. The article explores the optimization of homogenizing...