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Design of lattice structures for additive manufacturing using Selective Laser Melting technology
Vrána, Radek ; Maňas, Pavel (referee) ; Koutný, Daniel (advisor)
Metal additive technology allows to create objects with complex shape that are very difficult to produce by conventional technologies. An example of such component is a porous structure which is composed of periodical truss cells. This diploma thesis deals with the prediction of the mechanical properties of very small lattice structures made of additive manufacturing technology Selective Laser Melting. Using the proposed test specimens it was found that real dimensions of the trusses varies with size and orientation to the base platform. It was proposed and tested samples for rod tensile test made of SLM. Based on the real information about dimensions and mechanical properties of rods were predicted mechanical properties of lattice structures. A lot of mechanical tests were carried out to obtain the real mechanical properties. Test results and conclusions are described in the thesis.
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The origin of cracks in bulk aluminium alloys prepared by SLM technique
Tomeček, Michal ; Pantělejev, Libor (referee) ; Štěpánek, Roman (advisor)
This thesis aims to analyse the general character of manufacturing parts via the SLM (Selective Laser Melting) method, which belongs to the methodical group ALM (Additive Layer Manufacturing). In the first part the general technological process of SLM is described. In the second part the main focus is on the resulting influence of the procedural parameters and cons of using aluminium in SLM process. In the third and the last part the experiment is analysed. The main goal of this thesis is the research of influence of the procedural parameters on relative density and properties of aluminium alloys made by the SLM method and the analysis of the experiment that was carried out.
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Research on process parameters for producing of a structured material made by Selective Laser Melting technology
Richter, Vladislav ; Koutný, Daniel (referee) ; Vrána, Radek (advisor)
Selective laser melting (SLM) is one of additive technologies which allows manufacturing of components with very complex shape. One of the examples are porous lattice structures which are used in cosmonautics or medicine due to its good mechanical properties and low weight. In this work the influence of processing conditions (laser power and laser scanning speed) on material properties and geometry of as-fabricated trusses is investigated. Wide range of laser powers (100–400 W) and laser scanning speeds (1000–10000 mm/s) were used to determine optimum process parameters. Truss size, morphology and internal porosity was investigated using optical 3D scanner and X-ray micro computer tomography (mCT). Based on executed measurements optimum processing conditions were determined to be 350 W and 3000 mm/s. It is possible to manufacture faster geometrically more precise structures with equal internal porosity due to optimization.
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Experimental investigation of mechanical properties of structures made by metal 3D print
Porubský, Radek ; Jaroš, Jan (referee) ; Vaverka, Ondřej (advisor)
This bachelor thesis deals with shear testing of lattice structures produced by the Selective laser melting technology. The testing method was based on the ASTM D7078 standard, which deals with the testing of composites. BCC and FCC lattice structures with different strut diameters were selected for the experiment. The work describes the course and results of shear test. These real results are compared with results of finite element analysis. The results compare the properties of structures depending on the diameter of the strut, the type of structure or the direction of loading. The influence of Selective laser melting production technology on the properties of structures under shear loading is also discussed. For example, the results showed that the FCC structure has better mechanical properties under shear loading than the BCC structure. For both structures, it was also confirmed that structures with a larger strut diameter have significantly better properties than those with a smaller strut diameter.
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The study of the effect of additive manufacturing technology parameters Selective Laser Melting properties of the produced object
Žabka, Marek ; Koukal, Ondřej (referee) ; Vrána, Radek (advisor)
Metal additive technology currently finds use in a large number of industrial sectors. Mainly in domains such as aviation, medicine and astronautics, the emphasis is laid on mechanical and material properties of materials. This bachelor thesis deals with the research study of process parameters of technology Selective Laser Melting for material AlSi10Mg and stainless steel 316L. In thesis the impact analysis of main process parameters: laser power, scanning speed, hatch distance, layer thickness, especially on the porosity of the samples was carried out. Recommended settings for both materials were found based on the research of the current state. It was further found out the influence of parameters such as powder humidity or laser scan strategy.
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Design of rocker for mountain bike shock absorber using topology optimization
Zalibera, Tomáš ; Hurník, Jakub (referee) ; Vaverka, Ondřej (advisor)
Submitted bachelor thesis deals with research and comparison of topology optimization software. A given component is 3D scanned, after that, kinematics model is done to define possible load cases. Then, topology optimization is done in four selected software. Results from topology optimization are then validated in FE analysis to acquire maximum deformation and stress. After the FEA the best variant is chosen, which is additionally modified to reach sufficient level of safety factor. The discussion and conclusion chapter deals about final comparison of topology optimization software based on FEA resuls and the most suitable software is choosen, in which decrease of deformation by 27% was achieved with a level of weight a bit lower as with the original rockers.
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Methods for surface improvement of components processed using Selective Laser Melting
Krontorád, Martin ; Slavíček, Jakub (referee) ; Malý, Martin (advisor)
Power bed fusion is advantageously being used for manufacturing of not only critical automotive and aerospace components, but even for biomedical implants. As-built components suffer from poor surface quality. The quality of surface directly affects fatigue behaviour. Some of the commonly used surface finishing methods are not suitable for additively manufactured components with intricate geometries. This bachelor thesis is focused on description of suitable methods for such components. The centre of attention is on Ti-6Al-4V and Inconel 718. The impact of each one of the methods on mechanical properties is discussed. Lastly a procedure of surface finishing for model cases of theoretical components is proposed. The main takeaway from this paper is understanding the obstacle that poor quality of surface to additively manufactured parts is and different solutions, to this problem, that described methods offer. Subsequently a critical analysis of the usability of the methods and help with designing a surface treatment procedure is offered.
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Alloy copper processing of selective laser melting technology
Kočica, Martin ; Šafka, Jiří (referee) ; Paloušek, David (advisor)
This diploma thesis deals with finding copper alloy suitable for processing SLM technology and determining the process parameters leading to a relative density close to the full material. The theoretical part provides an insight into additive technology and the processing of new alloys in SLM. Work also contains a search report of processed copper alloys used in SLM. Based on the theoretical part were designed test samples and method of evaluation. Samples were produced by melting metallurgical powder using ytterbium laser with an output power 400 W. The testing is divided into three stages; Determination of the parameters of the SLM process, Debug strategies for larger parts, Geometric precision and mechanical testing. Based on the results was determined dependence of relative density on the input parameters. For the best parameters were determined geometric precision correction and mechanical properties.
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Evaluation of Mechanical Properties of Lattice Structures Made by 3D Metal Printing
Pliska, Jan ; Skřivánková, Vendula (referee) ; Vrána, Radek (advisor)
Additive manufacturing technologies allow manufacturing of complex structures which are near impossible to manufacture by other more conventional technologies. A fine example of these complex structures is a periodic metallic micro-cellular structure This bachelor thesis is focused on summarization of known mechanical behaviour of lattice structures manufactured via Selective Laser Melting. This study also investigates suitable comparison criteria for lattice structures. Required values for determination of material constants were obtained from mechanical testing of real specimens. For faster evaluation of mechanical testing, automatic script in MS Excel was created. Research showed up some of the major parameters characterising the mechanical behaviours of lattice structures. It is possible to compare qualities of lattice structures based on criteria presented in this work.
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