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In the current world, the business faces different challenges, as it was in the 1950th. Today, most of the manufacturing companies have a very strict approach to increasing market needs of Safety, Quality, Delivery and Cost key performance indicators (KPI). To stay competitive, it is needed, that a holistic approach on the improvement of strategic KPIs is needed in order to be successful. The target of this paper is to show the application of the Value stream mapping methodology, used in a case study for a finish good assembly line in an Electronic Manufacturing Facility. The study is showing the improvement of quality, delivery and productivity KPIs over a time period of 3 consecutive years. The result is the increase of production output from 500 pcs/shift to 1050 pcs/shift, decreasing the number of quality returns from 3 to 0 and improving the delivery performance from 95 to 100% against customer requested date.

In this work, the microstructure and mechanical properties of three types of high-speed tool steels (Vanadis 60, ASP 2052 and S 705) were studied. The steel S 705 was made by conventional ingot metallurgy technology, and other types of steels were manufactured by powder metallurgy technology. The studied steels were examined both in the soft state and further in the hardened condition with subsequent tempering. Microstructure of metallographic cuts and fracture areas was studied by electron microscopy. Hardness, tensile properties and notch toughness were determined. Significant differences in the properties of steels in both studied states have been documented.

The article deals with the optimization and modernization of assembly systems by creating models in the simulation software. The creation of digital models is a current trend in enterprise digitization called Industry 4.0. The Tecnomatix Plant Simulation environment allows you to create a virtual model of a real assembly line with the input of its basic production parameters. To perform the analysis, 8 real assembly lines were used, with an average of 15 workplaces, which were integrated into one universal line by means of simulation. The aim was to analyse the effectiveness of the proposed modernization universal assembly line using the generated statistical data.

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 current standards ISO 16610-21 and ISO 16610-22 were built in MATLAB for obtained signal filtering. The calibrating simulator simulated various master standard values, various probe arm starting positions before the calibration, various probe arm starting positions before subsequent common measurement, and tolerance limit utilisation during a master standard value transmission to the probe signal. An efficiency of signal linearization procedure was explored, as well. Obtained results are presented as signal zones, which delimit assigned signal deviations from perfect signal characteristic.

Additive manufacturing (AM) allows printing from different materials: from wax to plastic and even metal. This paper concentrates on Direct Metal Laser Sintering (DMLS), which allows printing to create complex parts from different kinds of metal. Inconel 718 was chosen for this research. This material is used especially in the aerospace industry and in other demanding applications due to its characteristic properties, which include high strength at high temperatures, corrosion resistance, low thermal conductivity, high hardness, work hardening and low thermal conductivity. Components used in aeroplanes must be very reliable, lightweight and their mechanical stresses must be accurately described, because the components are designed with respect to these criteria. For this reason, each material must be perfectly described in terms of mechanical properties and their minimum limits must be identified. Tensile testing is the best way to find the basic set of mechanical properties of a material. The samples were printed in two different orientations on a building platform and the differences in mechanical properties were investigated. The effect of machining on mechanical properties was also investigated.

In a competitive market the manufacturing companies have to produce cost effective products which can be realized by minimized production cost and higher effectiveness. The application of Lean manufacturing philosophy in order to optimize costs and quality is gaining a competitive advantage. There are lots of Lean tools which can result the improvement of the production line performance.
The article is original and unique, because beside the description of theoretical background relating to the process improvement, a practical method is also introduced in a case study.
In the study the author describes the main general steps of a Lean project completed in an industrial environment. The described case study which is a part of a real R+D project shows how can be improved the efficiency and reduced manufacturing cost of a real manufacturing system by application of several Lean tools which are One-piece flow, Takt-time analysis, Line balance and Cellular design.

This study analyzed the surface smoothness of some fuel briquettes produced from hazelnut, corn and sunflower residues. The residues were briquetted with different particle sizes (PS: 2-5 mm and 7-10 mm) under 80 MPa and 160 MPa. The surface smoothness of them were analyzed by image analyze from their high quality photos. In conclusion, it's seen obviously that the smaller particle sized briquettes had smoother surface than the ones produced with bigger PS. Furthermore, they had better results of compaction, toughness and physical properties.

The paper describes the surface roughness measurement of functional parts of tools for minting coins. The coining dies were coated with three types of coatings - CrN, TiCrN and WC/C. Roughness of the coining die surface is a very important factor for the quality of a struck coin. The quality of specific coatings on the coining die surface was evaluated by a contact (Hommel Tester T500 roughness measurement device) and contactless method (microscope Sensofar PLu neox) by using optical interferometry and confocal microscopy. Results from the shop measurement gained by using the roughness measurement device were compared to the laboratory measurements gained by using microscope. Moreover, results were illustrated in the graph. Measured values were identical. Only the CrN coating showed bigger difference. Minimum roughness value was measured on the coining die with the TiCrN coating. The WC/C coating reached the maximum roughness value. 3D visualization method of surface roughness using software Gwyddion proved inappropriate for burnished surfaces.

Cutting shop-floor experience often shows that after machining one lot the insert is changed and the next lot is started with a new insert. Thus the tool life of the cutting tool is not fully used. Therefore we analysed how to determine, after machining a lot with a given number, the number of pieces of the next lot that can be machined with the same insert. Based on the cutting experiments we determined wear curves for some specific parts. With the introduction of two new definitions (equivalent number of pieces and equivalence ratio) we elaborated a method with which the machinable number of pieces of the next lot can be determined - even if a lot is machined by other cutting parameters - until the tool life criterion is reached. Based on this method and using nomograms or an algorithm the further machinable number of pieces can also be determined.

Manufacture of new parts of machineries, devices, etc., especially in engineering and metallurgy requires machining of the feedstock in a mechanical way. During machining occurs immediate contact between the tested specimen and the tool and in their mutual relative movement of friction and wear. One of the possible variants how to eliminate this fact is the application of process fluids during machining.
Currently, we are trying to simulate long-term testing by laboratory testing called tribology. The experiment presents friction between two materials that are under real sliding contact. This article examines the tribological characteristics between two materials (tool - ball and workpiece material - disc). The paper contains findings when examining process fluids by tribological test Ball - on - disc, this test is currently used in practice, very widespread, this test can imitate various operations of cutting machining. This paper deals with the evaluation of tribological properties (the coefficient of friction, wear of disc and wear of ball) between the ball from ceramic material Si3N4 and the test material (stainless steel X5CrNi18-10, EN 10088-3 and steel commonly used in engineering 16MnCr5, EN 10084-94) by using two kinds of process fluids.

Article deals with design of jig for welding of rail-borne door system on the basis of model and drawing of window frame. Using this jig is ensured right setting and reliable clamping of two bent profiles. By welding of these profiles is made a window frame of automatic door systems for rail-bornes. TIG method is used for welding. Article describes and explains setting and clamping of window frame into jig. Design of control jig for window frames of similar type is embodied in text too. Control jig helps by dimension measurement of window frames.

New types of process fluids is very broad. Drilling with constant feed force represents the experiment that follows different properties and effects in machining. The main aim of this scientific paper is to assess the speed of drilling holes by the drilling technology-constant feed force- with the drilling cutting tools made of uncoated high speed steel. Eleven different process fluids were compared used the during the experiment. There were compared eleven different process fluids. In the context of the thesis more process fluids from global suppliers have been tested. In the process of experiments there were used twist drills of high speed steel type HSS, ČSN 221121, ø 8 mm, without coating. Steel samples were 16MnCr5, according to EN 10084-94. During the experiment there was used drilling of holes by hand feed drill machine V 20 that was modified with the mechanical switch and there was also stopwatch. Testing of process fluids in chip machining has been going on at the Department of machining and assembly of the Technical University of Liberec for many years.

Article deals with design of welding jig for assembly of wind power plant component. Mainstay of article is design of welding jig, which makes exactly setting and reliable clamping of individual parts of welded desing possible for their complete welding. Design procedure of individual parts of welding jig is described in details in view of their functionality. Paper is especially focused on the parts of welding jig, which are necessary to make, including material selection of individual parts. Finally the technical and economic evaluation is carried out, approximate cost of jig is calculated and financial savings associated with practical use of welding jig are evaluated.

This paper focused on axial flow pump high operation, reliability, and long service life at different frequency of rotation (DFR). The efficiency of an axial pump varies considerably depending upon the conditions under which it must operate. This article concentrates methods related to the reliability analysis of pumping system operation by a frequency converter. Initially, it is focused to analyze the behavior of individual characteristic curves of the axial pump to find how can be applied for the determination of the most efficient frequency of rotation. Axial flow pumps are often controlled by adjusting their rotational speed, which affects the resulting flow rate and output pressure of the pumped fluid. In addition, the head and flow of fluid transported at different frequencies of rotation, to produce a map of reliability characteristic curves to verify the similarity rules for pumps recommendable operating region are discussed. The results showed that the recommendable operating region for a different revolution per minute of axial pump can be determined with efficiency. If the axial flow pump is driven outside its operating region, the efficiency decreases, and the reliability and long service life may be affected.

Present work is focused on the study of recycled AlSi8Cu2Mn cast alloy. Furthermore, the effect of Sr-modification (0; 0.03 and 0.05 wt. %) on the microstructure, tensile and impact properties (UTS, ductility, hardness and impact energy) were investigated. For study and identification of intermetallic phases were utilized standard, colour and deep etching (in order to reveal the 3D-morphology of the Si-particles and intermetallic phases). For element composition of the specimen was used X-ray analysis. Finally, the effect of Sr-modification on silicon morphology was examined. The results show that the addition of Sr into AlSi8Cu2Mn cast alloy should act as a modifier, so it supposes to change the eutectic Si-morphology. However, its effect as a Si-modifier is not as significant. Higher number of iron (1.1 %) leads to an increase of precipitation of brittle iron phases with platelets (Al5FeSi) and skeleton-like (Al15(FeMn)3Si2) morphology. Al5FeSi platelets act as preferred crack sites and reduce the tensile and impact properties. Strontium not only refined and modified eutectic Si, but also modified the Al5FeSi needles and thereby improves tensile (first of all ductility) and impact properties. Sr addition is also associated with porosity formation.

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 tool life far shorter. For the test, taps with different threads per chamfer were used. The second part of the paper is focused on the experiment where cutting tool life was monitored.

The paper deals with welding joints and the methodology of increasing safety during austenitic chromium-nickel steels welding - type EN 10028-7 1.4301 (X5CrNi18-10). The technology of submerged arc steel welding 1.4301 using MAG enables a wider application of these steels in terms of the production of pressure vessels, but despite following all the safety regulations of heterogeneous welding stated in WHS, there might be an occurrence of melting defects of carbon parts through the welding of joints. The aim of this paper is to discuss the corrections of welding penetrations of the additional material during inhomogeneous welding, with the least possible destruction of the original material.

Although important improvements of prosthetic sockets has been implemented another investigation has been done also by solving problems with inadequate stump heating and from that resulting excessive sweating of limb. This phenomenon is further associated with leg volume changes. Therefore for realization of this research the model of prosthetic limb was created with socket that further addresses these issues of artificial limb. Throw the application of holes and tightening bells the pressure to remaining stump decreased and at the same time the heating of limb is lower. These results indicate that the implementation of these design modification will improve the comfort and fit of prosthetic devices in future.

This paper presents an improvement to the mechanical and tribological properties of aluminium alloys. AlSiN and AlCrSiN coatings (with different Cr content) were deposited on substrates of Al-Cu-Mg alloy by the cathodic arc evaporation method at 400°C. Surface morphology and chemical composition were estimated by a scanning electron microscope equipped with an energy dispersive spectrometer and mechanical profilometer. The increasing chromium content in the coating led to an increase in the coating hardness. The tribological behaviour of the coated and uncoated Al-Cu-Mg alloy samples was examined using the "Ball-on-Disk" method (ASTM G99-95) at a load of 10N using Al2O3 ball as a counterpart.

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 forces are evaluated. This paper is limited only to carbide tools. The results of the experiment are compared with results from other research institute.

Al-Zn-Mg-Cu alloys possess excellent mechanical properties, and therefore are used in aerospace and automotive industry. However, they are susceptible to localized corrosion such as pitting, intergranular and exfoliation corrosion, which is closely related to the precipitate size and distribution. Because the size and distribution of the precipitates are controlled by heat treatment, we investigated the influence of the heat treatment on corrosion behaviour and mechanical properties of the AA 7075 alloy. Audi test, internal Audi standard PV 11 13 for automotive industry, was chosen to evaluate the corrosion behaviour of the as-cast, T5 and T6 heat treated aluminium alloy 7075. Mechanical properties were studied through the tensile test and hardness measurements. The highest corrosion rate and the depth of corrosion attack penetration were observed for the T5 state, while the T6 state evinced the best resistance to localized corrosion and the highest mechanical properties.

Fractographic methods derive their knowledge from Euclidean geometry, set theory, metric theory and chaos theory. In engineering technology, the fractography is primarily used for modeling of fatigue and intergranular fractures. As such defects are not smooth due the principle of their origin, they cannot be described using ordinary mathematical tools. However, if the conditions of self-similarity are met, fractal geometry means can describe various irregular, incomprehensible, crooked or fragmented geometric shapes. Fractographic description of the fracture profile allows more accurate quantification of fractures and it also enables identifying possible causes of their initiation. This study contains several examples of specific cases of Cr-Ni steel failures and a basic explanation of their fractographic description.

Nowadays manufacturers currently use about 35 % of secondary aluminium and about 65 % of primary aluminium to meet their needs. The production of secondary Al alloys have significant advantages. Most important is saving of natural resources with a consequent material cost reduction and a considerable energy-saving associated to reduction in pollution and CO2 emissions. The positive fact is that secondary Al alloys has comparable mechanical properties with primary aluminium alloys. Therefore it is necessary to study properties such alloys especially those which are used for transport industry in order to keeping the quality of casting. One of the major properties of casting for transport industry are fatigue properties. Research point to the fact that more than 90 % of broken engineering components are fractures caused by fatigue of used material. Extremely dangerous are fatigue fractures in transport, for example rails, tire parts, plane wings and hulls of ships, because these are usually connected with human casualties. Due to this fact were studied fatigue properties of aluminium alloys used especially for automotive castings - AlSi9Cu3. The great object was influence of casting to the different mould (sand and metallic) without modification, heat treatments or grain refinement of experimental material to fatigue resistance of the casting. This work shows differences between materials properties which were casted into the different mould.

Firefighter ladders are manufactured of aluminium alloy AA 6063. These ladders are a widely used technical tool for firefighting, for intervening firefighters and for rescued persons. The quality of the ladders is checked by so-called "user test" which is a non-destructive deflection test defined by CSN EN 1147. Unfortunately, this test is not sufficiently conclusive in terms of safety. Therefore, the project called "Safety improvement of extension ladders for firefighters" (VI20162020021) is focused on the complex assessment of the existing firefighter ladders through mathematical modelling, material analysis and real testing. In the present work structure and mechanical properties of samples (aluminium alloy AA 6063) taken from different areas of a firefighter ladder are presented. The obtained result confirm excellent mechanical properties of selected samples, such as tensile yield strength and ultimate tensile strength, at laboratory temperature but a huge decrease in these properties after exposure to temperatures above 200 °C for even short times. This results in the necessity to control temperatures in the proximity of the ladder, especially in the case when the ladder is located near a flame.

This article presents the metallurgical and material properties of castings from stainless steel G-X4CrNi13-4 and G-X4CrNiCu13-4, which can be obtained under the conditions of the Foundry shop of PILSEN STEEL s.r.o. The article mentions furnace units of primary and secondary metallurgy in which the stated quality steel is produced. By way of illustration of achieved properties of melt, the heat analyses and micro-purity of steel are shown. Mechanical properties of steel are represented in well arranged graphs showing achieved values of the yield point, tensile strength, and impact energy at various temperatures, such as for example: 20, -10, -20, -30, -40, -50 a -60°C. By way of illustration, there are figures of the castings most frequently produced from stainless steel in the Foundry shop of PILSEN STEEL s.r.o. In the end, the article points out what effect has micro-purity of steel on the value of impact energy.

NiTi alloy exhibits the shape memory effect, which implies the application in medicine and also many industrial branches. This paper is devoted to the manufacture of these alloys by the use of powder metallurgy using reactive sintering. This method could enable easier production of this alloy and achievent of higher purity. However, for the optimization of this technology, the deeper knowledge of the mechanism of the process is needed. This work uses microscopy on real powder mixtures subjected to reactive sintering, as well as on model samples processed under various conditions.

This work deals with the problematics of 3D printing. Additive manufacturing (AM) covers a lot of principles of producing products and prototypes, for example, Direct Metal Laser Sintering (DMLS). This principle is based on sintering metal powder in thin layers, layer by layer. This theme is very extensive and a very popular research area. The paper is focused on printing thin walls. The material for printing was Maraging Steel MS1. This material achieves great mechanical properties like as high strength and high hardness. The tensile strength can be up to 2000 MPa after age hardening. The printer used was an EOS M290. The effects of different part position on safety of printing are compared. Also, the effect of support structures on accuracy was investigated. The main part of the paper is focused on an experiment where thin walls are printed and subsequently evaluated. The influences and limitations were investigated. The measurements were carried out on a Blickle Multicheck PC500 microscope.

Dimensional changes, or distortion, play a very important role in carburizing. To keep carburizing process productive and profitable, it is crucial that the resulting distortion is minimized. The purpose of this experiment was to carry out low-pressure carburizing and measure dimensional changes, residual stresses, characterize the resulting microstructures, and determine hardness in the specimens. These are the most important clues to the quality of the carburized layer. Experimental materials were the most widely-used carburizing steels: C15, 16MnCr5 and 15NiCr13. Residual stresses in the surface were determined by X-ray stress measurement.

The paper deals with a study of actuator (brake cylinder) modification for generation of braking force in a brake unit. The original solution, carried out using the original brake cylinder in cooperation with the proportional pressure control valve, is sufficient in terms of correct function of the brake unit, but in terms of safety, the corresponding force sensor may be damaged in case of a control circuit proportional pressure valves defect. Another reason for the study is utilization of the total regulation range of the proportional pressure valve and improvement of the brake unit response time in case of braking force overload. Such overload results in tread or rotating rail surface damage. The article gives description of the currently implemented passive measures to increase safety against sensors damage, but also of proposed active measures to eliminate these defects by changing size and type of the brake cylinder.

To design an optimal support of a large shade sail it is necessary to determine forces in wire ropes that support the sail. Relations between a sail loading and ropes reaction forces, rope diameters and sail stresses were investigated. To simulate the sail behavior and set up these relations, numerical (FEM) models were created and analyzed. Most of the results show nonlinear relations between above mentioned parameters and they depend on the sail geometry, applied loads and the rope diameter. It means that for every specific geometry and loading of particular sail an optimal rope diameter and support should be designed. The nonlinear numerical analysis is very suitable tool for this purpose and thus specialized systems based on the Finite Element Method (FEM) should be used to simulate and analyze such problems.