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Determination of Material Properties of Specimens Produced by Metallic 3D Printing
Zakl, Alexandr ; Peterková, Eva (referee) ; Řiháček, Jan (advisor)
This bachelor's thesis deals with mechanical properties and current status of 3D printing of metal parts, especially by DMLS/SLM method. Research part is dedicated to various technologies and suppliers in the field of 3D printing with emphasis on printing metal methods. Main purpose of this thesis is to connect the worlds of 3D printing and 3D optical measuring of deformation, so the part of research segment is dedicated to optical measuring and leading innovative company GOM. One of the leading product of this company is ARAMIS and in the context of this thesis it was present during the experiment as a instrument for measuring and inspecting material characteristics, and is present in research part where is mentioned a principle on which this device is working (digital image correlation) as is the device itsself. In the experimental part of this thesis, samples were printed on DMLS printer from company XactMetal, which were then submitted to a tensile test. Measurement was done using DIC based device ARAMIS and inspected for basic material properties in same named program.
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Properties of Metallic Materials Prepared by Cold Spray Technology
Piňos, Jakub ; Šiška,, Filip (referee) ; Čížek, Jan (advisor)
Cold spray is a novel coating method. Due to its low-temperature character, it has a potential to replace the high-temperature thermal spray processes in some applications. The presented work analyzes the microstructure and the phase composition of pure metal coatings deposited by cold spraying and evaluates selected mechanical properties. Specimens prepared by readily used HVOF industrial technology were used for comparison purposes.
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Computational simulation of the compression test of the open cell metal foam
Homola, Václav ; Skalka, Petr (referee) ; Ševeček, Oldřich (advisor)
The thesis presents computational simulation of compression test of a nickel foam and the 3D reconstruction of micro-CT images was utilized to generate the foam’s model of geometry. Explicit FEM is used to simulate compression test using software tool LS-DYNA and the stress–deformation curve is obtained together with deformed model’s mesh used for subsequent analysis. Sensitivity analyses were performed to configure the model and ensure best fit with values obtained during real-life experiment. The ANSYS Classic environment was then used to simulate tensile test of the foam compressed to various thicknesses. The tensile moduli in three mutually perpendicular directions of nickel foam were computed and the results were compared to experimental values as well. The results of tensile test simulation revealed considerable anisotropy of the foam’s elastic behavior. It can be said that the measured experimental data correspond very well with the elastic properties obtained from simulation up to certain level of compression. Analysis of the relationship between the element size and tensile moduli showed a significant difference between fine and coarse mesh. The optimal level of discretization and the overall model configuration ensuring high level of accuracy is proposed in this thesis.
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Optimalization of parts bonded by hot crimping
Liškář, Ladislav ; Řiháček, Jan (referee) ; Lidmila, Zdeněk (advisor)
The thesis describes the procedure for verifying the conceptual ideas of the company. Design and production of prototypes, testing and evaluation, quantifying savings. Two variants of crimped bond were chosen. For each was length of shaft changed to three and four crimped grooves. These prototypes were tested in two static and one dynamic tests. Recommendation for company is continue with other phases of development for shaft with four grooves.
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Hardenning of polymeric composites by nanotubes
Kuběna, Martin ; Zajíčková, Lenka (referee) ; Pantělejev, Libor (advisor)
This diploma thesis focuses on the influence of carbon nanotubes (CNTs) on the mechanical properties of a composite material with polyurethane (PU) matrix. The material was supplied in the form of thin films with thickness from 0.2 mm to 1.2 mm. The theoretical part of this thesis describes the production technology, properties and applications of composite materials PU/CNTs, and also deals with preparation technology and properties of both components of this composite material separately. The theoretical part also describes the principle of tensile testing of polymer materials. The experimental part of the thesis was primarily focused on comparing the tensile properties of a composite material PU/CNTs with tensile properties of pure PU. At first, tensile properties of pure PU were investigated, while the influence of various factors like strain rate, specimen thickness, heat treatment and aging was examined. In adition, stress relaxation tests and tests with strain rate jumps were performed on pure PU specimens. Then composite PU/CNTs was tested in tension and the results were compared with the results of tensile tests of pure PU. Composite material PU/CNTs was prepared with various concentrations, so it was possible to determine the effect of CNTs content on the tensile properties of the composite. The last part of this thesis deals with tensile tests of PU composite material with functionalized carbon nanotubes (PU/FCNTs), where the influence of surface modification (functionalization) of CNTs on the tensile properties composites was investigated. It was shown that the effect of both CNT and FCNT on mechanical properties of the composite is not significant. This conclusion was discussed on basis of the works of other authors, which do not unambiguously proved the positive effect of CNT or FCNT on mechanical properties of composites with polymer matrix.
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Comparison of tensile properties of polymeric samples produced by extrusion based 3D printing
Krajcar, Ivo ; Vespalec, Arnošt (referee) ; Škaroupka, David (advisor)
The subject of this work is a summary of the contemporary knowledge about 3D printing and mechanical properties of a prototype manufactured this way. Main goal is to compare the frequently used FDM method with the innovative APF method of 3D printing from the Arburg company. ASA and CPE materials were chosen for researching this method. On these materials, tensile strength was measured. Aditionally, for comparison between the two methods, referential samples manufactured by injection moulding were made. A percentual difference in strength of each sample was compared against these. 60 samples in total were made for this comparison. After evaluation of the results, it was found that in the tensile strength the samples made by the APF method are approximately 30 % less strong than the referential sample. The samples made by the FDM method are approximately of the same strength as the referential sample.
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Controlled life-time polypropylene
Demková, Eva ; Petruš, Josef (referee) ; Tocháček, Jiří (advisor)
The master´s thesis is focused on the characterization of degradation process of polypropylene and polypropylene with statistic copolymer into which manganese (II) stearate and cobalt (II) stearates were added at 0.05, 0.10 and 0.20 wt.% loadings. The aim of the thesis was to prepare the controlled life-time polypropylene. The degradation was studied at varying temperatures and prodegradant loadings. The prodegradants were synthetized and characterized using the FTIR and DSC techniques. Thermooxidation of the tested samples induced the changes in crystallinity, melting points and melt-flow indexes. Tensile strength and other mechanical properties were determined by means of the tensile test. The carbonyl index was determined using FTIR, the thermooxidation stability test was used to determine the activation energies of reactions. The changes in morphology of degraded samples were observed by SEM analysis.
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Influence of input material on technology and production of deep drawn product
Černá, Monika ; Peterková, Eva (referee) ; Šulák, Ivo (advisor)
This bachelor thesis was elaborated in cooperation with company ITW Pronovia, s.r.o within the scope of the bachelor degree and presents an assessment of the effect of material properties and manufacturing technology of a deep-drawn product. In this work the mechanical and technological tests were carried out on the supplied material HT179. This material is further processed into a cartridge for an airbag deployment. During production many defects occurred, especially after cutting out the holes of deep-drawn product. The company established these defects as material property. Therefore it is necessary to evaluate the characteristics of different material sets.
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Mechanical properties of 3D printed PLA plastic parts
Novosád, Ivan ; Dočkal, Kryštof (referee) ; Paloušek, David (advisor)
3D printing is being widely used by public and also in industry. The main advantage of 3D printing is rapid making prototypes. That is the reason why it is needed to know what the mechanical properties of the material that is being used are. This thesis is about making research of knowledge about 3D printing and mechanical properties of printed parts. Main task was comparing materials used in 3D printers and find out which producer makes materials with the best tensile strength. 5 producers were selected to be compared in this test. From each producer was bought PLA filament in natural colour, this material was then used to print testing specimens. All specimens were tested on maximum tensile strength and Young's elastic modulus and then was calculated the confidence interval for each producer.
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