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The topic of the article is the increase of cutting conditions in the machining of heat-resistant steel using exchangeable inserts. The main part is the design of a new technology for machining one of the heat-resistant materials using replaceable inserts, including a discussion of any defects and economic evaluation. The aim is to reduce production costs and contribute to the elimination of production times. These modifications of technologies have a positive effect on the overall economy of produc-tion and the use of new methods in practice. Heat-resistant steels have found application in many branches of production, especially in the aerospace industry for jet engine components. Their specific properties need a more detailed examination of the optimal conditions for their processing.

The geometric accuracy is significant property of the product. For semi-finished products, this accuracy may also affect the accuracy of the final product (the resulting mechanical component). Geometric accuracy (inaccuracy) can be transmitted from one operation to the next in production - technological heredity arises. It is, therefore, essential to analyze the deviations on the produced areas and take measures to ensure that the negative effect of one operation was not transferred to the next operation. It is insufficient to analyze only the numerical values of the measured deviations. It is necessary to directly analyze the measured profiles in the field of macro geometry. The paper presents a stability analysis of roundness profiles measured on the drawn tube. The analysis uses knowledge from harmonic analysis and from the Fourier series. The measured roundness profiles are divided into individual harmonic components. Arithmetic means of amplitudes of individual harmonic components are moni-tored. There were analyzed parameters determining the stability of the profile - standard deviations.

Multilayer synthetic leather-like textiles are traditionally manufactured by using dimethylformamide as a diluent via polymeric polyurethane coating and coagulation processes. Unfortunately, this process has a strong environ-mental impact since it encompass a complex and polluting grinding process to separate dimethylformamide from water. Furthermore, this compound was proved harmful for both environment and textile practitioners’ health. The aim of this work is to improve the state of the art in the production of leather-like fabrics through the devel-opment of an innovative process of coagulation of polyurethane in aqueous solution to replace the current highly polluting process that involves the use of dimethylformamide. The coagulation is obtained by means of a IR ther-mal fixing thus resulting in a completely eco compatible manufacturing process. The obtained quality of the man-ufactured synthetic leather, tested according to textile standards, is comparable to the one obtained by means of conventional processes.

This paper investigates the replacement of a conventional steel coil spring with a composite disc spring with the aim of minimizing its weight. Simulation in the CAD system Siemens NX 12 was used to determine the composite disc spring’s behavior. The regression functions were stated based on the numerical simulation. Based on the regression functions the solution with the minimum weight was found using software programmed in Matlab. The prototype discs were manufactured from carbon fibre prepreg. Their load-deflection characteristics were tested and compared with the designed values. The experimental results show that using this solution reduces the weight by about 30% in this case.

Currently, companies have been trying to make the use of their technology, manufacturing capabilities and experienced workforce to respond flexibly to market demands. Collecting and processing of all relevant data in the company is one of the key points to which increased attention should be paid so as to maximize the efficient use of own resources and consequently ensure a continuous reduction of pro-duction costs. The article deals with the use of burning machines in engineering company. The product range involves the production of burnouts from standard and special materials as well as welded steel parts of structures. The company has long struggled to optimize the material and information flow between particular production operations. This paper was focused on information flow logistics, which proved to be the biggest weakness of the central material preparation department during the bottleneck analysis. The scientific contribution of the resolved issue can be seen mainly in the possibility of inter-connecting process analysis and optimization of material and information flows.

The use of modern production techniques such as 3D printing brings new requirements for shaping ma-chine parts. In the case of the production of the runner blades of Kaplan micro-turbine using 3D printing technology from plastic, the emphasis is on the mechanical properties of the blade and hydraulic proper-ties of the entire turbine. Achieving the required parameters is conditioned by finding a suitable shape of the runner. Therefore the design, virtual testing, optimization and evaluation process is automated. The paper describes the whole process where virtual testing of hydraulic parameters is performed by CFD simulations, and the methods of genetic algorithms are used for optimization. Selected final geometrical shapes of the blade are subjected to a more detailed analysis of hydraulic parameters in the wider oper-ating range and also to the strength analysis.

This experiment assesses the suitability of square-welding high strength steel using the deep penetra-tion welding method, RapidWeld. The aim of this method suitability assessment was to compare the final material properties of three welds, welded accordingly to identical welding procedures. High strength, ultra-fine-grain steel S1100QL (XABO 1100) was used as a parent metal. The suitability con-firmation was based on the achievement of requested mechanical properties of ISO 15614-1 and mo-bile crane manufactures standards. The hardness, strength properties and impact energy measure-ment and evaluatioon of the joint was performed during the experiment. The joint was welded re-peatedly with the use of the same welding parameters for the confirmation of process stability. The achieved mechanical properties fulfill all the requirements. The hardness value deviation is caused by different properties in the heat affected zone. The root cause of the impact energy deviaton was not fully investigated, but the minimal measured values are above requirement. The deviation of the strength characteristics is mininal. The performed experiment has confirmed that the selected weld-ing method is suitable to ensure that the requested material properties of welded high strength, ultra-fine-grained steel are achieved.

Nowadays, Carbon Fibre Reinforced Polymer (CFRP) materials are extensively used as substitutes for metal parts in aircraft and automotive components since they are lighter in weight. However, mi-cro drilling CFRP materials during the assembly process poses various challenges such as low hole accuracy and delamination. Hence, an experiment has been executed to investigate the influence of micro drilling parameters towards hole accuracy. The spindle speed and feed rate are the machining parameters that have been considered in this experiment. Three different optimum parameters have been obtained from previous experiments, involving the spindle speed combinations of 8,000, 10,762 and 11,017 min-1 with a feed rate of 0.01 mm/rev. A drill bit with a diameter of 0.9 mm is used to drill approximately 300 holes. It has been revealed that the combination of the spindle speed of 11,017 min-1 and feed rate of 0.01 mm/rev produce high hole accuracy at the 2nd hole compared to the 300th hole due to the presence of uncut fibres at the 300th hole which have reduced the hole area. Hence, out-come of this research could provide the benefit to the industries in term of manufacturing time and materials expenditure.

Exploded view is a kind of schematic view which decomposes the assembly into parts and arranges according to certain rules to explain the product structural relationship and guide the relevant technical personnel to carry out product assembly or maintenance. It is necessary to consider the visibility constraints and explosion sequence rules to construct the exploded view. Manual creation will lead to repeated modification and low efficiency. In this paper, a projection based algorithm for automatic generation of exploded view is proposed. In this method, the explosion set of products is constructed based on disassembly matrix and the assembly sequence of complex products is represented as a set of ordered hierarchical exploded view, so as to ensure that the exploded view can clearly express the feasible assembly sequence. The projection interference detection method is proposed to ensure the visibility of the exploded view under a given angle of view, and the method of selecting the explosion direction is proposed to improve the compactness of the generated exploded view, and the explosion direction guideline is established to improve the readability of the exploded view. The algorithm has small storage space, fast search speed, and is not limited to a single specific perspective, so it is more general. The feasibility and efficiency of the algorithm are verified by an example of automatic generation of explosive drawing of fixture model.

The production of automotive products from polymeric materials represents operations associated with the flow of material during its shaping to the desired final mold. The technological aspects of the processing of polymeric materials are closely related to the rheological properties. The article deals with adding technological waste from production to virgin material and its influence on rheological or flow properties of selected polymer composite. The analyzed material is used in the manufacture of components (connectors) in the automotive industry. The rheological properties were measured in two stages. In the first stage, rheological properties were assessed in the short term immediately after preparation of the test samples. In the second stage, half of the samples were exposed to elevated temperature and the effect of aging on the rheological properties of the material was monitored. Based on measured MVR values before exposure to elevated temperature, it can be said that the amount of process waste does not significantly affect the flow properties of the polymer. After exposure to elevated temperature, there is a significant decrease in polymer flow properties probably due to the crystallization of the macromolecular chain.

The presented paper deals with the design of a knee simulator that uses pin-on-ball configuration, ie cartilage and CoCrMo head. The translational motion consists of the cartilage and the rotating head when the load of the articulating pair is derived. The simulator meets the predetermined kinematic conditions according to the ISO 14243-3 standard, including dynamic loading. The simulator is able to record the coefficient of friction during the test, which helps to understand the biotribological processes in the knee. The structural part of the simulator is preceded by a research part, in which the existing simulators and tribometers, which helped to create this design, are analyzed. In the experimental part, specific elements (drives, sensors, etc.) are selected that meet the defined boundary conditions, and the method of friction measurement is determined. The paper concludes with an overall evaluation of the proposed knee joint simulator, which will be able to achieve the conditions according to ISO 14243-3 and at the same time record the course of the coefficient of friction between the cartilage surface and the CoCrMo head.

In this work the influence of material type and sample fill density was evaluated. One PLA material was tested. Test specimens having different fill structure and density were printed from this material. Full honeycomb and gyroid shapes were used for the fill structure. The specimens had four different fill percentages for each structure: 10%, 25%, 50% and 75%. These bodies were compared to samples that were printed with 100% fill. Tensile test was performed on printed test pieces. The Zwick / Roell Z100 was used for testing and the surface hardness of the test specimens was measured by the Shore D method on a DIGI-Test II hardness tester. Fracture surfaces were evaluated on an Olympus DSX 500 optodigital microscope. The results showed that the shape of the fill did not signifi-cantly affect the values obtained by the tensile test. The hardness measurement results showed a different hardness on the bottom surface that was in contact with the printing pad and the top printing surface. Fractographic analysis revealed different types of fracture surfaces related to the printed fill structure.

This work deals with the construction of a steel hangar with a sheet metal shell for storage sports flying equip-ment (SPE) or general aviation aircraft. The design of the building was made to ensure an individual approach to each aircraft. The construction was designed with price and safety in mind. An available option is an electronic security system connected to the central security desk via the Internet, mobile phone or other data transmission.

The results of researches on porosity and structure of castings from AlMg9, AlSi7Mg and AlCu4Ti alloys produced by squeeze casting and for comparison by gravity die casting are presented. The tests were carried out on 200x100x25mm plates squeeze casted under 90MPa pressure. Prior to the commencement of experimental studies, numerical simulations of solidification were made for the selected alloy (AlSi7Mg) in order to determine the potential locations of shrinkage porosity. As part of the study, the porosity distribution in the plate cast was assessed by taking samples for measurements from the center and edge of the casting. It was found that the area particularly vulnerable to the presence of shrinkage porosity is the central part of the casting and the zone extending from its center to the upper surface. Due to the wide temperature range of solidification of the examined alloys, diffused porosity occurs in castings, and the shape of the pores formed is conditioned on the solidification morphology. The average porosity of squeeze castings is two times smaller than gravity die castings and is at the level of 1.0-1.5% depending on the type of alloy. In addition, as a result of pressing, the shrinkage porosity in the central part of the plate is reduced and its distribution becomes uniform throughout the volume. High pressure acting on solidifying castings ensures a significant increase of grains density in microstructure and decrease of SDAS.

The paper presents the results of an experimental research and a numerical calculation of a multi-gap seal of a centrifugal pump. The experimental research allowed to obtain the characteristics? performance of the multi-gap seal at different operating modes, in dependence on the axial size of the chambers, pressure distributions? changes, and a leakage from the seal. Using finite volume methods, values of radial hydrostatic forces, pressure distribu-tions and leakage values were obtained. The results of the numerical calculation were compared with the results of the experiment, which showed that they matched.

In this paper, the possibilities of selective laser melting (SLM), one of metal additive manufacturing technologies, in the preparation of trabecular structures are discussed. Despite great advantages in geometrical freedom, there are specific process-inherent aspects that must be considered before the production of such structures. To verify SLM capabilities, we tested different orientations (horizontal and vertical) and thicknesses (0.2-4.0 mm) of single struts. Significant irregularities in strut thickness and deviations from the designed cross-sectional area were observed. Horizontal struts showed greater geometrical deviations. Based on our observations, a trabecular structure was prepared with all struts inclined 45° from the building platform. Due to the 72% porosity, mechanical properties approached those of the bone, which is beneficial for the application of such structure in orthopaedics for bone tissue substitution.

The article compared the strength results of single-lap adhesive joints made of galvanized steel sheet. The strength of adhesive joints was determined for two methods of surface treatment - using a degreaser (method B) and with-out a degreaser (method A). The samples were joined using a two-component epoxy adhesive based on Bisphenol A. The strength tests were carried out on a Zwick/Roell Z150 testing machine. The analysis of the surface roughness parameters of the samples for the method A was performed. The highest shear strength value (8.82 MPa) was ob-tained by method B and using P120 abrasive paper. The lowest shear strength value (4.08 MPa) was received using method A and P600 abrasive paper. The maximum values of measured surface roughness parameters were rec-orded for samples prepared with abrasive papers with granulations, respectively: P120, P220 and P180. The low-est values of Ra, Rz and Rt parameters gained using P600 abrasive paper.

Optimization is the process of finding the best possible solutions of a problem. It has been widely used in various areas especially in engineering problems. One of the common issues that is faced by some of manufacturers is finding drilling sequences of multiple holes. By drilling multiple holes with the least total path length, the manufacturer can save a lot of time and it can increase the productivity of the company. Thus, this study focuses on drilling path of multiple holes problem which has been solved by other researchers. This study uses the Bees Algorithm to find the best sequence of drilling holes (mini-mum total path length) and the results found are compared with the result of other algorithms. In addi-tion to results comparison with other algorithms, the results obtained are verified with simulation results using MasterCAM software. The results comparison shows that the Bees Algorithm achieved compara-ble performance compared to other algorithms.

Accuracy of work-pieces of complex free form surfaces is achieved by tolerancing, producing and metrology of workpieces. The tolerance zone is defined by form tolerances, their orientation and location on the work-pieces. Tolerances for complex form surfaces are specified by line profile tolerance or surface profile tolerance. These tolerances control form or combination of size, form, orientation and location. In a machining process the impact of machining parameter settings on the final surface quality will be researched. The influence of toolpaths in connection with the SH (Scallop Height) parameter setting on production accuracy and quality of machined surface will be compared. For geometry verification of the complex form surfaces are coordinate measurements used. The measurement area is modeled with the equations in CATIA V5. The data of machined surface obtained through the contact coordinate measurement are processed using the coordinate system adjustment via the RSS minimization by the Newton method in Matlab/Octave. Calculated values of surface profile deviations at individual machining strategies are used to achieve the required quality of machined surface through optimization of the machining parameters.

Aiming at the evolution balance problem of hybrid assembly line (HAL), a dynamic (evolution) balancing model of assembly line is established, and a cooperative optimization algorithm (PSO-GA) is proposed in this paper. Firstly, HAL evolution in the market diversification and technology progress environment is studied, and assembly line evolution balance is mainly considered. In the PSO-GA, minimizing the number of stations, minimizing the load indexes of between stations and within each station, and adjusting costs are used as optimization objectives. For increasing population diversity and speeding up the searching speed, the individual information exchange and mutation are carried out in the populations. Finally, the effectiveness and feasibility of the method were proved by optimizing the HAL for an enterprise.

An emulation study of the drilling by the spade drill on the spinneret micro-hole is conducted by using FEM analysis software Deform-3D. According to application of finite element software Deform-3D, some characteristic parameter of the work piece and the cutting tool material are set. The distributed situation of cutting force, cutting temperature and tool wear in different cutting parameters are simulated analysis. By discussing the location of the spade drill drilling wear, further optimization of parameters cutting and tool for the spinneret micro-hole drilling provide the better basis.

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.

From the initial feedstock to the final product, the manufacture of forged parts is a highly complex process in which a large number of technological factors play their role. These factors are associated with temperature and the amount and rate of deformation. Developing a manufacturing route often involves major effort being put into finding optimum production parameters with respect to boundary conditions which mainly comprise customer requirements and financial aspects. In order to determine an optimum set-up for forging production or to introduce a new technology, a number of essential steps must be taken and sometimes repeated. In this context, material-technological modelling is a promising and effective tool which enables numerous optimization phases to be carried out in a laboratory environment without disrupting the operation of production lines in forge shops. The present paper describes material-technological modelling of production of a closed-die forged part of microalloyed steel involving the use of controlled cooling. The objective of this investigation was to define the processing window for microstructure evolution, depending on the forging temperature, the amount of deformation, and the rate of cooling from the finishing temperature.

A big accent is put on environmental protection at the present time. Noise belongs in general to negative factors of our environment. For this reason, it is necessary to perform suitable measures in order to eliminate noise. For example, it is possible to apply sound absorbers in order to damp noise. Materials with porous, spongy and fibrous structure belong generally to suitable materials in terms of noise damping. The aim of the paper is to investigate sound absorption properties of different types of porous materials. Frequency dependencies of the sound absorption coefficient over a frequency range of 150-6400 Hz were determined by the transfer function method using the acoustic impedance tube. Different factors, that have influence on sound absorption of the investigated porous materials, were studied in this paper. It can be concluded that sound absorption properties of the tested porous materials are significantly influenced by material structure and thickness, excitation frequency and air gap size behind the investigated samples.

We need to create appropriate and effective numerical (FEM) model to optimize properties of a composite product. The creation and evaluation of an efficient numerical model that could be used for an analysis of layered composite is the aim of this work. The model has to be able to take into account the properties and layout of the individual layers and must allow effective change of these parameters; thickness, material and number of layers especially. Various models of the same product are created and compared. The models differ in the type of used FEM elements. The results of models (deformation primarily) were compared with the result of analytical computation. Further, time and computational requirements of individual models are also evaluated. Element types used for investigated models are: 1D elements, 2D plane stress solid elements, 2D plane strain solid elements and shell elements. Models created form 1D and shell elements showed a close agreement with the analytical solution, and they provide the appropriate tools for the definition of layered structures and for the analysis of results.

Burnishing is a cold working process with superficial plastic deformation, which is to exert an external pressure through a very hard and smooth roller or ball on a surface to occur a uniform and work-hardened surface, to make it possible to reduce roughness, to increase the hardness and to produce residual stresses of compression. The unalloyed S 355 J0 steel specimens were machined on a conventional lathe to the proper dimensions; these machined specimens were then burnished by a simple locally designed and fabricated roller-burnishing tool. The main objective in this work is to determine a mathematical models statistically based on experimental design (response surface methodology) using central composite second-order rotatable design which allows to give the relationship between the two out parameters surface roughness and hardness, representative of the superficial layer surface caused by the four internal roller-burnishing parameters called: burnishing speed, force, feed and number of passes of the tool. The experimental results indicate that feed, burnishing force and speed are the most important and significant parameters to improve roughness surface, and feed, speed, burnishing force and number of passes are the most important and significant parameters to improve superficial hardness of S 355 J0 steel specimens. The surface roughness and hardness were improved from about 2.5μm to 0.15μm and from 176 HV to 226 HV respectively. The validated models with coefficient of determination R2 = 93.1% for surface roughness and R2 = 89.8% for hardness, seem correlate well with the experimental results.

The paper gives practical using of thermovision for quality casts assessment, which are casting to permanent moulds. Thermovision allows monitoring temperature of moulds and their cooling process by refrigerant medium in foundry engineering. It helps when the problems with elimination internal defects exist. Tests in experiment were implemented by DAS scan and local surface modification of water cores of cylinder heads. Cylinder heads are produced by ROTACAST foundry technology. Results of experiment showed that in location of defects is no directionally solidified. It is necessary to modify tools to defect eliminate. Tests consist of four parts. Each test has its contribution to improve the situation. The last test, when were implemented the heating cartridges was most effective and the problem was eliminated.

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. The mechanical properties were evaluated by the tensile test, impact bending test and Brinell hardness test. Fatigue tests were realised at sinusoidal cyclic push-pull loading (stress ratio R = -1) at ambient temperature (T = 20 ± 5 °C). They were carried out in the high cycle fatigue region (from 105 to 107 cycles) at frequency f ≈ 75 Hz using the fatigue experimental machine Zwick/Roell Amsler 150HFP 5100. The relationship between the amplitude of stress σa and the number of cycles to failure N, as well as the fatigue strengths, were determined.

Fatigue properties of the constructional materials belong among the very important material parameters, mainly because they are very closely related with the total fatigue life of the part. Knowledge of the boundary between limited and infinite (endurance) life represents a truly very important fatigue parameter. This paper deals with the influence of pre-deformation on aluminium alloy AW-5182 fatigue properties. These tests were performed under fully reversed harmonic cycle (max/min stress ratio R = -1). As a major aim there was determination of so-called S-N curves (stress vs. number of cycles) and their mathematical description by the Basquin's equation via fatigue strenght coefficient σf' [MPa] and fatigue strength exponent b [1]. Measured S-N curves gave a basic overview about the basic pre-deformation influence on the alluminium alloy AW-5182 fatigue properties.

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 (to 240, 360, 480, 600, 720, 840, 960 and 1080). Totally 9 basic files was obtained. In the conclusion of the paper lists of all results are presented together, with their mutual comparison and prediction of the possible development of tool wear at higher number of cutting edges.