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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Experimentální komora pro testování speciálních materiálů technologií SLM / Experimental chamber for testing of special materials using SLM technology

Malý, Martin January 2017 (has links)
The thesis deals with the influence of process temperature and pressure on 3D printing using Selective Laser Melting. The aim of the thesis is the design, manufacture and testing of the experimental chamber for SLM 280HL from company SLM Solutions. The main task of the experimental chamber is to increase the temperature of the preheating of the powder bed from the original 200 °C to at least at 400 °C. The device will be used to investigate the influence of high process temperature on the properties of printed materials. The thesis also deals with the design of the powder applicator for elevated temperatures.
22

Zpracování vysokopevnostní hliníkové slitiny EN AW 7075 technologií SLM / Processing of high-strength aluminum alloy EN AW 7075 using SLM technology

Skalický, Petr January 2017 (has links)
This diploma thesis deals with processing of high strength aluminum alloy EN AW 7075 by Selective Laser Melting and verify the influence of process parameters on relative density and mechanical properties. The theoretical part contains an introduction to additive manufacturing of aluminum alloys, the influence of process parameters and description of processes occuring during SLM production. Based on the theoretical part were prepared experiments and method of evaluation. Samples were produced by melting metallurgical powder using ytterbium laser with a maximum output power of 400 W. This diploma thesis also describes the formation and growth of cracks inside the material, which so far in the literature for alloy EN AW 7075 were not described. As the result, the process parameters dependence on the relative density and an overview of this aluminum alloy processing by SLM technology is determined.
23

Optimalizace těhlice formule student pro výrobu SLM technologií / Optimization of axle carier for formula student for SLM fabrication

Vaverka, Ondřej January 2017 (has links)
This diploma thesis deals with design of axle carrier for Formula Student. The axle carrier is topologically optimized and additively manufactured with Selective Laser Melting technology. Material for its production is aluminium alloy AlSi10Mg, which has worse mechanical properties than commonly used high-strength alloys. Therefore the aim was, by using topology optimization, to design a component, which would have comparable properties with milled component. The stress strain analysis was carried out by the finite element method and maximum deformation and safety coef-ficients were acquired. The prototype was made and its dimensions were controlled by optical digitization, which proved accuracy of manufacturing. The strength calcu-lations were verified by special testing device and photogrammetry measurement. The load during the tests was 20 % higher than in the analysis and no limit state was observed. This verified its safety and functionality.
24

Analýza vlivu recyklace práškové oceli na porozitu dílů vyráběných technologií Selective Laser Melting / The impact of metal powder recycling on the porosity of parts produced by Selective Laser Melting

Sůkal, Jan January 2017 (has links)
Diploma thesis deals with the influence of recycling of powder steel 1.2709 on porosity of parts processed by SLM technology. Theoretical part of this thesis gives an overview of the influence of selected process parameters of this additive technology on the porosity of manufactured parts. The presence of pores in the material is the main cause of worse mechanical properties compared to conventionally manufactured materials. Since the advantage of this technology is the possibility of wasteless production, one of the possible causes of pore formation and degradation of properties of the powder material is due to standard recycling by means of sieving to remove the contaminants generated during the construction. This paper compares the porosity of parts produced by two different machines, analyzes the possible consequences of sieving on powder properties, establishes recommendations for setting the recycling process, and compares the degree of influence of process parameters on porosity.
25

Návrh pístní skupiny rychlého magnetoreologického tlumiče s využitím technologie selective laser melting / Design of fast magnetorheological damper piston group using selective laser melting technology

Vítek, Petr January 2018 (has links)
The diploma thesis deals with the development of the magnetic circuit of Magnetoreological (MR) dampers with a short time response. To achieve a short response time, a shape approach was chosen whereby the geometry of the magnetic circuit was chosen to significantly eliminate the occurrence of eddy currents. The influence of structures on magnetic properties was first examined on a simpler toroidal core and then the optimization was subjected to the magnetic circuit of the MR damper itself. Geometry optimization was done using FEM simulations. The resulting geometry was made of pure iron using Selective Laser Melting technology (SLM). In addition, a MR damper was completed and its properties on air and with MR fluid were measured, which were then compared with previously developed rapid MR dampers. It has been found that the newly designed magnetic circuit achieves similar time responses as all other compared fast MR dampers and reaches a higher dynamic range than most of the compared variants. The proposed magnetic circuit also has a significantly reduced weight.
26

Použití protlačovacích zkoušek na miniaturních discích pro materiály s vyšší úrovní strukturní nehomogenity / The use of small punch tests for materials with a higher level of structural inhomogeneity

Gordiak, Michal January 2020 (has links)
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.
27

Vývoj procesních parametrů technologie Selective Laser Melting pro výrobu lisovací formy pneumatik / Development of SLM process parameters for manufacturing of mold segment for molding tires

Měchura, Lukáš January 2018 (has links)
The diploma thesis deals with finding suitable process parameters for the production of molding segment by SLM technology. It consists of a combination of structures, shells, thin slats and bulk parts. The tested material is maraging steel 300. The research part deals with the problem of choice of suitable process parameters, such as laser power and speed, hatch distance and thickness of the built layer. The achievable mechanical properties of the parts and the choice of the suitable structure were also examined. In the thesis were found suitable process parameters for printing of bulk parts and structures.
28

SLM 125 Single Track and Density Cube Characterization for 316L Stainless Steel

Goss, Cullen 01 June 2019 (has links)
Selective Laser Melting is a rapidly developing additive manufacturing technique that can be used to create unique metal parts with tailormade properties not possible using traditional manufacturing. To understand the process from a most basic level, this study investigates system capabilities when melting single tracks of material. Individual tracks allow for a wide range of scan speeds and laser powers to be utilized and the melt pools analyzed. I discuss how existing studies and simulations can be used to narrow down the selection of potentially successful parameter combinations as well as the limitations of interpretation for single track information. Once we attain a solid understanding of what parameters perform well at a bead level, we can move onto looking at complete 3D parts. A challenge we have faced is creating near fully dense parts and determining a reliable density measurement technique that is accessible for operators at our university. Our results show that the previously determined optimized scan speed and laser power can consistently create parts with >99.5% density over a range of sizes using an analysis method utilizing readily available equipment and software.
29

Geometrická přesnost výroby kovových dílů aditivní technologií Selective Laser Melting / Geometric Accuracy of Additively Manufactured Test Parts

Ilčík, Jindřich January 2013 (has links)
The presented diploma thesis deals with the control of the geometric accuracy of the parts produced by additive manufacturing technology selective laser melting. The paper first analyzed the work of the other authors dealing with this issue. Based on obtained informations from this analysis were developed benchmark test parts for quality control of production on a commercial machine SLM 280 HL supplied by SLM Solutions GmbH. The work was carried out several tests to determine the appropriate parameters of construction parts. These tests, their results and conclusions are fully described in this papper.
30

Zpracování slitiny 2618 pomocí technologie selective laser melting / Processing of alloy 2618 using selective laser melting technology

Dokoupil, Filip January 2015 (has links)
This diploma thesis deals with finding and verification of appropriate technological parameters of SLM technology for the processing of aluminum alloy 2618. In the theoretical part, an introduction to additive manufacturing of aluminum alloys and general description of processes occurring during SLM production is given. Based on general knowledge were designed different types of testing samples produced by sintering the metallurgical powder using 400 W ytterbium fiber laser, which so far in the literature for aluminum alloy 2618 were not described. As the result, the technological parameters dependence on relative density and the detailed overview of the 2618 alloy processing by SLM technology is determined.

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