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The use of small punch tests for materials with a higher level of structural inhomogeneity
Gordiak, Michal ; Řehořek, Lukáš (referee) ; Válka, Libor (advisor)
Master's thesis deals with evaluating applicability of correlation relationships between material characteristics determined by Small Punch Test and standard tensile test for material AlSi7Mg0,6 manufactured by casting and technology SLM. Results of Small Punch Tests are correlated with yield strength, tensile strength, elongation, and Young's modulus of elasticity. For each material characteristic various correlation methods are compared, while for each method corresponding coefficients are determined. Consequently, the applicability of individual methods is evaluated by substituting coefficients determined by various studies. Primarily analyzed are correlation methods for which future normalization is expected. The results of master's thesis show that structural inhomogeneity caused by SLM process does not result in high inaccuracies in determining material characteristics. Larger impact on material characteristics has high porosity, which was identified in cast material and led to significant deviations in evaluating tensile strength and elongation.
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The mechanical properties of AlSi9Cu3 aluminum alloy processed by SLM technology
Koutný, Filip ; Skřivánková, Vendula (referee) ; Paloušek, David (advisor)
This bachelor thesis aims to compare mechanical properties of cast AlSi9Cu3 aluminium alloy with its state after processing by the selective laser melting (SLM) technology. The theoretical part of this work presents general characteristics of aluminium alloys, focusing on their classification, mechanical properties and heat treatment as well as SLM technology processing. In the second part, we further discuss optimal processing parameters of the SLM 3D printing technology and compare mechanical properties of the conventionally cast AlSi9Cu3 alloy and the alloy processed by the SLM technology.
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STUDY OF ENERGY ABSORPTION IN MICRO – STRUT LATTICE STRUCTURE PRODUCED BY SELECTIVE LASER MELTING
Vrána, Radek ; Schleifenbaum, Johannes (referee) ; Skalon, Mateusz (referee) ; Paloušek, David (advisor)
Předložená dizertační práce je součástí většího výzkumného projektu, který si klade za cíl využití mikro prutové konstrukce vyrobené technologií SLM jako absorbér rázové energie s přesně navrženými vlastnostmi. Hlavním cílem práce je vývoj numerického modelu deformačního chování mikro-prutové konstrukce vyrobeného technologií Selective Laser Melting (SLM) z materiálu AlSi10Mg. Aby bylo možné dosáhnout hlavního cíle dizertační práce, bylo nutné analyzovat vliv procesních parametrů technologie SLM na tvorbu vnitřních materiálových vad a drsnost povrchu při výrobě mikro-prutové konstrukce. Tyto imperfekce degradují její mechanické vlastnosti a jejich odstranění zlepší možnosti a přesnost numerické predikce. Výsledky ukazují významný vliv dvou hlavních parametrů – skenovací rychlosti laseru a výkonu laseru. Na základě těchto poznatků byly dále definovány parametry vstupní energie Ein a lineární energie Elin, které zahrnují oba zmíněné parametry a byly definovány jejich limitní hodnoty pro minimalizaci vzniklých imperfekcí. Deformační chování vyrobené mikro-prutové konstrukce bylo analyzováno na navrženém pádové zařízení, které umožňuje testování s dopadovou energií až 120 J. Deformační chování je vyhodnocováno s využitím obrazové analýzy záznamu vysoko rychlostní kamery a silového průběhu z tenzometru. Výsledky analýzy byly využity pro validaci numerického modelu v programu ANSYS Explicit, do kterého byly implementovány poznatky o reálném tvaru vyrobeného mikro-prutového materiálu ve formě eliptického modelu geometrie a informace o reálných mechanických vlastnostech ve formě vyvinutého materiálového modelu. Výsledné porovnání výsledků experimentu s predikcí numerického modelu ukazují dobrou shodu v místě maximálního zatížení Fmax (odchylka 5 %) i průběhu celé deformace vzorku. Tyto poznatky budou v budoucnu využity při návrhu absorbéru energie s definovanými mechanickými vlastnostmi.
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Optimization of SLM process for manufacturing of assault rifle muzzle device
Kubrický, Jakub ; Majzlík, Pavel (referee) ; Vtípil, Jaroslav (advisor)
The thesis deals with optimization of the manufacturing process of the muzzle device designed for assault rifle. The most common titanium alloy named Ti-6Al-4V was chosen for this task. The introduction summarizes previously existing types of muzzle devices and further describes the SLM technology with a special focus on titanium alloys processing. The optimization methods and their follow-up testing were designed according to theoretical knowledge that is summarized in the theoretical part of this work. Firstly, the aim was to describe the optimization of the manufacturing process with attention to preserving the relative density of the parts. Secondly, the mechanical properties of the parts that underwent different heat treatment were tested.The obtained data were then used to design and manufacture a muzzle device that underwent further testing in real condition afterwards.
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The use of surface modification for enhancing mechanical properties of SLM bulk materials
Barinka, Michal ; Řehořek, Lukáš (referee) ; Jan, Vít (advisor)
This diploma thesis deals with the surface modification of 3D printed metallic materials. The research part presents the most used methods of additive manufacturing and their process parameters influencing the quality of printed components. Defects arising during these processes and the techniques used to eliminate them are also described. In the experimental part of the work, the optimization of electrochemical polishing parameters was performed. The aim was to modify the rough surface of the components and thus prevent the formation of defects on the surface. The mechanical properties were investigated by means of three-point bending under static and dynamic loading. Fractographic analysis was performed on the quarry surfaces.
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Development of a strategy for 3D printing of copper using Laser Powder Bed Fusion
Kryšpín, Vojtěch ; Vaverka, Ondřej (referee) ; Malý, Martin (advisor)
Copper sees vast usage in aeronautical, electrotechnical and energy industries due to its excellent machinability and thermal and electrical conductivity. In combination with modern computational approaches such as topological optimalization, additive manufacturing of copper has a great potential. My work has focused on creating a sample with the highest relative density through the application of recoating and remelting strategies. The best specimens which reached relative density over 99,1% were created with the following printing parameters: LP = 400 W, LV = 400 m·s-1 a HD = 0,01 mm.
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Design of additively manufactured oil-water heat exchanger for formula student
Březina, Josef ; Dočekalová, Kateřina (referee) ; Koutný, Daniel (advisor)
Diploma thesis deals with a design and manufacture of oil cooler by technology Selective Laser Melting for Formula Student. The main goal of the design is to ensure optimal oil circuit cooling at a minimal mass. The design of manufactured oil cooler is based on a plate heat exchanger concept with optimized intakes by CFD simulations and heat exchange body with fins of thickness 0.17 mm. An analytical model was created. SLM process parameters were optimized for a thin walls printing, Subsequently, a fabrication of testing parts was finished for measuring pressure drops and performances of micro heat exchangers. Results were used for an accuracy improvement of the analytical model and for consequent optimization of heat exchange surface. Afterwards optimization was executed for inlets and outlets by using flow simulations. A prototype was built and verified on a test stand. Performance of the designed oil cooler is 4.5 kW for race mode, where temperature drop of oil circuit is 22 °C. The lightweight design weighs 320 g, which reduces more than 47 % of a current oil-air cooler weight. Furthermore, a centre of gravity is decreased by designed placement of the cooler.
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3D Lattice Structures for Application in Selective Laser Melting technology
Červinek, Ondřej ; Škaroupka, David (referee) ; Vrána, Radek (advisor)
Additive technologies allow manufacturing of components with very complex shapes which are difficult to manufacture with conventional technologies. Among these technologies belongs the Selective Laser Melting (SLM). Suitable applications of SLM include manufacturing of light-weight 3D structures like lattice structure or an organic geometry called gyroid. This bachelor thesis is focused on creation of models of gyroid structure and its application to parts followed by manufacturing with SLM. Series of models were made with mathematical software. Implicitly defined equation were used for better geometry coordination of created models. Options utilization and manufacturability of gyroid structures were tested within application into turbocharger impeller. At the end of this thesis was successfully manufactured the impeller including two types of gyroid structure (single-gyroid and double-gyroid)
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Universal muzzle device for an assault rifle
Rušar, Filip ; Majzlík, Pavel (referee) ; Vtípil, Jaroslav (advisor)
This diploma thesis deals with the design of a universal muzzle device for the assault rifle. The device is designed to produce Selective Laser Melting. The main objective is the elimination negative effects of gunshot. The paper explores possibilities of using porous structures for this type of equipment. The influence of individual types of porous structures on the flow of gases is monitored. The universal muzzle device itself is optimized using CFD analyzes. The device was made using SLM technology and experimentally verified. His impact on the impact, gun lift, noise and flame elimination was investigated.
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Development of 3D metal printing process parameters for producing of the lattice structure
Jaroš, Jan ; Koutný, Daniel (referee) ; Vrána, Radek (advisor)
Selective laser melting (SLM) in additive technology, which allows production of lattice structures. Lattice structures are very difficult to produce using conventional methods. The main use of lattice structures is in aerospace industry and medicine for bone implants production. In this work influence of processing parameters (laser power, scanning speed) on properties (diameter, surface roughness, porosity) of struts is investigated. The processing parameters selection was based on single tracks test. In the first test, ImageJ was used to determine porosity of struts. In the second test porosity was analyzed with more accurate µCT technology. Both tests used 3D scanning technology to determine dimension accuracy and surface roughness of samples. The measurement results led to the detection of processing parameter „window“ where samles had the best combination of surface roughness and porosity. The best results were achieved with 225-275 W laser power and scanning speed of 1400-2000 mm·s-1.
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