Manufacturing Technology Journal, 2017 (vol. 17), issue 1

Analysis of the Joint between Blade and Stator Disc in Steam Turbine

Sona Benesova, Antonin Kriz, Petr Benes

Manufacturing Technology 2017, 17(1):3-7 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/3  

The use of a new method of attaching fixed blades to a stator disc led to the need for evaluating the strength of a riveted joint. Conventional mechanical testing revealed large variations in the strength of this joint. After sectioning the joint, it was found that the shank did not fill completely the hole in the shroud of the disc. Further investigation involved numerical simulations using the DEFORM software, because securing additional samples for physical examination was complicated. The first simulation task focused on determining the tearing-out force, taking into account work hardening of the shank material due to plastic deformation. The second...

Study of Phosphate Formation on S355J2 HSLA Steel

Kamil Borko, Filip Pastorek, Stanislava Fintová, Martina Neslušan-Jacková, Branislav Hadzima

Manufacturing Technology 2017, 17(1):8-14 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/8  

In present paper, the growth process of the phosphate coating on S355J2 steel was investigated. The microstructure, surface morphology, coating thickness, surface roughness and corrosion resistance of the phosphate coating were analysed by using several techniques including light microscopy, confocal laser scanning microscopy (CLSM) and electrochemical tests - electrochemical impedance spectroscopy (EIS) in 0.1M Na2SO4 solution (simulation of industrial atmosphere). The phosphate coating formation was evaluated after chosen exposure times from 15 minutes to 105 minutes in phosphating bath composed of MnO2, H3PO4 and demineralised H2O. The optimal exposure...

The Influence of Mould Strength on Shrinkage Production for Castings with Different Wall Thickness for Material EN-GJS-400-18LT

Martin Conev, Iveta Vasková, Martina Hrubovčáková

Manufacturing Technology 2017, 17(1):14-18 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/14  

This paper is dealing with the influence of mould strength on a shrinkage production for ductile iron castings. According to pressures that impact a mould cavity the strength of mould is an important parameter by ductile iron pouring. During the solidification of cast iron a non-metallic particle - graphite is released. Depending on graphite amount released in the liquid and in the solidified skin of casting the tendency to shrinking is varying. In the experiment a furan sand mixture is used. The experiment compares a size of the created shrinkage in the castings with different wall thickness poured into a moulds with different strength. For the occurrence...

Cutting Tool Life when Tapping Nickel Based Super Alloy

Milan Daňa, Miroslav Zetek, Václav Schorník

Manufacturing Technology 2017, 17(1):18-23 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/18  

This work deals with the issue of tapping Inconel 718 alloy. This material is known for its unique properties of high strength at high temperatures, corrosion resistance, high hardness, work hardening and low thermal conductivity. The machinability of Inconel 718 is very hard and cutting tool wear is high.This paper deals with creating internal threads by using monoliths taps. The taps are made of powder metallurgy high speed steel.The taps were provided with coating. Preparation of the hole for the thread has a huge impact on the cutting tool life. If the preparation is poor the inner face of the hole will be work hardened. This makes the cutting...

Effect of Cutting Edge Geometry on Cutting Forces when Drilling Inconel 718

Milan Daňa, Miroslav Zetek, Václav Schorník

Manufacturing Technology 2017, 17(1):24-29 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/24  

This work deals with the problematics of cutting forces when drilling holes in Inconel 718. Drills with different geometries of cutting edge were used. The cutting forces and torques were measured during the experiment. The feed cutting force had the greatest influence of all the cutting forces, therefore only the cutting force feed was evaluated. The torque was monitored. This material is known for its unique properties of high strength at high temperatures, corrosion resistance, high hardness, work hardening and low thermal conductivity. Part of the paper is focused on the experiment where the effects of the geometry of the cutting edge on cutting...

Effect of Heat Treatment Conditions on Micro Structure of Cast Iron

Štefan Eperješi, Miloš Matvija, Marianna Bartošová, Daniel Fecko, Alena Pribulová

Manufacturing Technology 2017, 17(1):29-33 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/29  

Article deals with problematice of influencing mechanical properties - tensile strength and hardness - of grey cast iron by heat treatment - refinement. Refinement could be in special cases applied also for grey cast iron castings in order to achieve special parameters of hardness and tensile strength of parts for specific purposes. Hardening and tempering of casting sis commonly used for ductile cast iron, but in special cases could be applied also for grey cast iron castings. Refinement - hardening and tempering - was provided on samples from materiál EN GJL 150, EN GJL 200 and EN GJL 250. Afterwards, measured values of tensile strength, hardness...

Optimization of the Pressure Porous Sample and Its Manufacturability by Selective Laser Melting

Pavel Hanzl, Ivana Zetková, Josef Mach

Manufacturing Technology 2017, 17(1):34-38 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/34  

New concept for pressure testing samples has been designed based on previous experiments which investigated the maximum load capacity of a Schoen Gyroid. This pre-experiment pointed to the possible lack of measurements and newly designed pressure samples intended to improve measurement accuracy. This paper focuses on the manufacturability of the designed samples made by selective laser melting, which is able to produce complex metal parts using support structures. However, removing the support structures from a porous core is impractical. In this context, the ability to substitute supporting structures by a Schoen lattice structure is also marginally...

Influence the Composition of the Core Mixture to the Occurrence of Veining on Castings of Cores Produced by Cold-Box-Amine Technology

Martina Hrubovčáková, Iveta Vasková, Martin Conev, Marianna Bartošová, Peter Futáš

Manufacturing Technology 2017, 17(1):39-44 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/39  

Method of cold-box-amine is widespread and frequently used technology for the production of cores. [1] Characteristic defect castings of ferrous alloys, which often accompanies the use of amine - Cold box cores are veining . Survey , it was found that 77 % of those surveyed foundries have problems with veining, 71 % foundries solves this problem ( or try to tackle ) anti veining ingredients in nuclear and molding compounds , but only 29 % considered their " antiveining " method for successful and favourable. [2] Article discusses the possibilities of elimination veining. Ingredients called additives lower the temperature at which the SiO2 begin to...

Comparison of the Structure of CuZn40MnAl Alloy Casted into Sand and Metal Moulds

Pavel Kejzlar, Jiří Machuta, Iva Nová

Manufacturing Technology 2017, 17(1):44-48 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/44  

CuZn brasses are used for manufacturing highly stressed structural comonents. Their mechanical properties as e.g. strenth, toughness or wear resistance are affected not only by their chemical composition, but also by their structure. This paper is dedicated to the study and comparison of the structure of sand- and metal mould casted Cu40Zn alloy. Scanning electron microscopy supplied by energy dispersive spectroscopy and electron backscatter diffraction were used to evaluate the structure of both samples. Casting into the metal mould produces approximately five times finer grain structure compared to the sand mould. EBSD orientation mapping revealed...

Tricanter Production Process Optimization by Digital Factory Simulation Tools

Jiří Kyncl, Tomáš Kellner, Richard Kubiš

Manufacturing Technology 2017, 17(1):49-53 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/49  

As a result of globalization the aspects of raising productivity and speed of production with extreme requests on the flexibility of the production systems are gaining importance. These aspects of production are affected by type of product and production and mainly by the capability of companies to correctly manage the manufacturing process. Manufacturing process is globally quicker than it was and the areas of logistics and production planning are still gaining more importance. Gradual changes are also in complexity of production. Without modern tools for production planning it would be very hard to manage production effectively. These tools are part...

Maintenance Audit: the Tool for Maintenance Management Quality of Manufacturing Equipment

Václav Legát, Zdeněk Aleš, Tomáš Hladík

Manufacturing Technology 2017, 17(1):53-62 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/53  

The purpose of this paper is to provide an overview of state-of-the-art of maintenance management audit and to show a case study of maintenance audit and its results in the Czech Republic. Authors proposed audit methodology based on world and own experiences. It was defined hundred thirty audit criteria divided into ten maintenance management areas. Using expert approach to review of maintenance managers and documentation according to audit criteria enables to obtain answers and their assessment presented in percentage of audit criteria fulfilment. After that there is applied SWOT analysis method to determine mainly weakness (gaps) in real maintenance...

Analysis of the Impact of the Construction of a Gate on the Macroscopic Structure of a Casting and Its Influence on the Mechanical Properties of Castings

Ján Majerník, Ján Kmec, Monika Karková

Manufacturing Technology 2017, 17(1):62-66 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/62  

The macroscopic structure of a casting has a direct impact on its mechanical properties. The porosity and homogeneity of a casting closely correlate with its tear strength characteristics. In order to achieve the best mechanical properties, it is necessary to eliminate internal defects in a casting. The elimination of such defects can be achieved through the suitable adjustment of the input parameters of high pressure die casting machines prior to starting the actual casting cycle. This method is useful for companies that produce castings on the basis of supplied pressure forms, whereby it is impossible to influence the design of the gating systems....

Effects of Aluminium Microparticles and Surface Treatment of AlCu4Mg on Mechanical Properties of Adhesive Bond Strength

Miroslav Müller

Manufacturing Technology 2017, 17(1):66-71 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/66  

The aim of the research was to evaluate the lapping length, the adhesive bonded surface treatment and the influence of the filler in the form of the aluminium microparticles on the adhesive bond strength. The alloy AlCu4Mg was the adhesive bonded material bonded by means of a two-component epoxy adhesive used in construction of machines. The filler in a form of aluminium microparticles was added into the adhesive. Laboratory experiments were performed on normalized testing samples of alloy AlCu4Mg prepared under standard ČSN EN 1465. Within the research three various treatments of the adhesive bonded surface were evaluated, i.e. without the surface...

Tension of the Surface Layer in Machining Hardened Steels

Karel Osička, Zuzana Fišerová, Jan Otoupalík, Josef Chladil

Manufacturing Technology 2017, 17(1):72-76 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/72  

The article builds on the existing results of machining testing hardened bearing rings. Some significant results were already achieved in this area. Cubic boron nitride as cutting materiál has been tested and the results were published. Existing measurement proves that values which reaches prescribed level of tolerance IT 4 can be achieved in series production. The evaluation indicater of arithmetic average surface roughness profile deviation was reached in the range of Ra = 0.2 to 0.4. Cutting conditions have also been specified in a certain range of machining. The problem remained on surface integrity. Specifically, the state of the surface layer....

Cost Modeling for ABC Failure of Machines

Alena Pešková, Peter Demeč

Manufacturing Technology 2017, 17(1):76-79 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/76  

In this paper we analyze Weibull generated failures of equipment in discrete production. At first we will classify failures using ABC analysis. Obtained characteristics of each group of failures can be used to generate time of their occurrence and duration which are essential for assessment of their cost. We use optimization tool Solver from MS Office - Excel to solve problem of maintenance of machines. We optimize strategy of maintenance also according to cost of failures in categories ABC classification. Results of this optimization are tables, graphs, having that it can offer to managers a new unconventional access at the efficiency of investment....

Injection Molding Quality Improvement by Advanced Virtual Simulations

Karel Raz, Martin Zahalka, Zdenek Chval

Manufacturing Technology 2017, 17(1):79-83 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/79  

Main aim of this article and research is to describe exact influence of key parameter in injection molding process. This key parameter is temperature. Nowadays is possible to use wide range of advanced virtual simulation tools, which were in research used. Article is focused on determining optimal temperature of injected plastic material, temperature of mold and temperature of coolant. For veryfing of virtual method was performed real injection molding with same input parameters and results were compared. For evaluating of achieved quality was investigated influence on whole molding process and influence on final product properties. As testing material...

Theoretical Regulation of Delimitation of Metal Level Decrease in the Furnace in Case of Pneumatic Dosing Device of Metal

Juraj Ružbarský, Rastislav Majerník

Manufacturing Technology 2017, 17(1):84-86 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/84  

Article deals with the during operation of pneumatic dosing device designed for die casting machines where the metal level in the furnace decreases stepwise by which the period of dosing of the filling mould is prolonged. We also deal the regulation of delimitation of metal level decrease in the furnace based upon the pneumatic principle.

Production of High Frequency Elliptic and Hyperbolic Optic Mirrors

Josef Sedlak, Dusan Muzikant, Petr Valasek, Karel Kouril

Manufacturing Technology 2017, 17(1):86-94 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/86  

An article provides an overview of production and corresponding issues of one of the most important component of a satellite dish - a high frequency optic mirror that polarizes signals caught by a parabola into a sensor connected to computing (so-called receiver).The article describes an issue of production of high frequency elliptic and hyperbolic optic mirrors forming one of the most important functional components of parabolic satellites designed for ALMA, the biggest and the highest located international astronomic radio telescope in the world. It is situated at a high plateau Chajnantor in Chile, South America.Individual parts of the article...

Importance of Diffusion Process on the Fatigue Life of Steel

Zbyněk Studený, David Dobrocky, Zdenek Pokorny

Manufacturing Technology 2017, 17(1):94-99 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/94  

Evaluation of the diffusion process is the plasma nitriding technology in connection with an increase of fatigue life of steel. For experiments steels 41CrAlMo7-10 and 34CrNiMo6 were selected. The equivalent of mentioned steel is material no. 1.8509 and no. 1.6582. Plasma nitriding technology belongs to the group of chemical-heat treated process. This process includes the saturation of nitrogen to the core of material. Plasma nitriding technology is effective method usage in practise especially in order to increase the surface hardness, corrosion resistance and fatigue strength. The experimental material samples were heat treated and subsequently plasma...

Results if Machining by Tool of Self-Propelled Rotation Due to Wear

Karol Vasilko, Jozef Pilc

Manufacturing Technology 2017, 17(1):100-103 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/100  

On the base of a well-known method of machining with disk-shaped rotating tool the self-propelled tool was designed. The principle is based on braking the tool rotation during machining, until the moment of determined wear criterion on the tool flank. As with the growth of tool wear the force of cutting resistance increases, it is possible to use it for automatic tool swinging into a new position by which a new part of cutting edge comes into engagement. The paper describes the tool design, theoretical analysis of Rz after machining and actual experimental machining results.

Usage of Waterborne Acrylate Anticorrosion Systems for Ecological Environment

Jiri Votava, Vojtech Kumbar

Manufacturing Technology 2017, 17(1):103-110 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/103  

All technical metals used not only in agriculture are subject to degradation processes, there are distinguished two main types: mechanical abrasion and physical-chemical degradation (corrosion). In order to lower abrasion of a machine part, it is necessary to use appropriate technical materials as well as an appropriate heat treatment. To minimize losses caused by corrosion, an appropriate anticorrosion system has to be used. This paper evaluates corrosion and mechanical resistance of waterborne acrylate anticorrosion systems sold on the Czech market. These paints were applied by an air flow technology. Mechanical characteristics of the applied coating...

A Method of Computer-aided Modular Fixture Design, Part 1: Creating the Feature-model Repository of Fixture Elements

Zhun Wang

Manufacturing Technology 2017, 17(1):110-114 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/110  

Modular fixture is conventionally designed less concerning the detailed specifications of machine tool. A little of literatures involve the effectively application to the existing CAD systems in CAFD (computer-aided fixture design). The determination of the validity of modular fixture during NC machining lacks for a practical method. This paper put forward that: Firstly, the feature-model repository of elements of modular fixture can be built in CAD packages; the design of modular fixture in NC machining should be accomplished under the concept of NC Manufacturing System (NMS); the Post-NC verification can be applied to check the performance of modular...

Tool Life of PM-HSS Cutting Tools when Milling of Titanium Alloy

Pavel Zeman, Pavel Bach, George Trmal

Manufacturing Technology 2017, 17(1):115-121 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/115  

Machining of titanium alloys meets with poor life of a cutting tool. It is caused by a low thermal conductivity and by a high strength-to-weight ratio of the alloys. Various approaches for cost-effective and productive machining titanium alloys are still researched. One of methods can be using the cutters made of modern high-speed steel (HSS) as a product of a powder metallurgy (PM) process. These materials (PM-HSS) possess better and homogenous mechanical properties than conventional high-speed steel. The PM-HSS cutters equipped with any effective coating allow increase cutting speed to the level which is typical for uncoated cemented carbide, while...

Influence of the Workpice Quality on the Cutting Tool Life when Gear Wheel are Machined

Miroslav Zetek, Ivana Zetková

Manufacturing Technology 2017, 17(1):121-125 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/121  

The stability of the machining process is depending on the machined materials properties. But the material properties are influence by the heat treatment process and in this case it is forging. For these study three different company made the "same" forging process and then the material properties are evaluated and their influences on the cutting process were monitored. For the tests the steel DIN 18 CrNiMo 6-7 was used. This material is typically used for the gear wheels where the cutting tools by tool steel is used for the machining. So for the tests the mills from tool steel were used and during the machining the cutting tool life and cutting forces...

Kinetics of Gas Emissions from Moulding and Core Sands, Gasification Patterns and Protective Coatings - the New Investigation Method

Jerzy Zych, Jan Mocek

Manufacturing Technology 2017, 17(1):126-131 | DOI: 10.21062/ujep/x.2017/a/1213-2489/MT/17/1/126  

Gases evolving from moulds, cores, coatings deposited on sand and metal moulds constitute one of the basic reasons of several casting surface defects: blow-holes, pinholes, pitted skin, etc. In research performed up to now the moulding sands gas evolution is determined in two ways: normalised, in which the gas amount emitted from the sample placed in a heated flask is determined or in the other way, in which the gas amount emitted from the core - covered with liquid metal - is determined. In these both methods the result constitutes the total amount of gases emitted from 1g of a moulding sand and the emission procedure as a time function. The new method...