National Repository of Grey Literature 38 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Influence of process parameters on the roughness of the cut during laser cutting of stainless steel thickness 3 mm
Novotný, Jan ; Hála, Michal (referee) ; Mrňa, Libor (advisor)
Theoretical part of the thesis provides an overview of the most often used laser devices in industry and their main domain of application, especially focused on laser cutting. It also explains measuring of surface roughness and thermal cuts qualification. The experimental part deals with the roughness measurement of stainless steel samples cut by a fiber laser and statistical evaluation of influence of process parameters (pressure, speed and power) on the kerf roughness in regard of ČSN-EN-ISO 9013.
Experimental chamber for testing of special materials using SLM technology
Malý, Martin ; Dočkal, Aleš (referee) ; Koutný, Daniel (advisor)
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.
Procedural parameters at Inconel 625 cladding
Hrádek, Jan ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
The research is focused on cladding of inconel 625 using the MAG - CMT method. It was found that welding without an oscillation does not create the necessary geometry to establish additional layers. When welding with an oscillation, it was researched that the current between 150 and 200 A appears most appropriate in the synergistic mode for welding inconel 625. The resulting weld bead was made at a current of 190 A with pulse dynamics correction set to -4 and correction of arc length to +10 and welding speed of 315 mm per minute.The weld bead was not ideal mainly due to insufficient height. The improvement of results could be achieved by set oscilation with fluent change in acceleration. Because of the time options and difficulty of programming it was used only constant speed for all experiments.
The study of the influence of process parameters on the roughness of the cut for flame laser cutting of stainless steel
Kučera, Václav ; Hála, Michal (referee) ; Mrňa, Libor (advisor)
Thesis presents a study of the influence of process parameters on the roughness of the cut surface. The test material is 1.4301, namely austenitic stainless steel. When a parameter is the surface roughness not change too much. In some samples there were defects in the form of cutting burrs. The graphs below show the estimated minimum change one parameter (the lowest point of the curve). As the most important parameter from a technological point of view, cutting speed, constitutes a major cost item compared to the auxiliary gas and power. For samples with a thickness of 2 mm and 3 mm has been achieved good results with decrease in the cutting rate of 30% percent, although when cutting the samples with a default rate was almost identical results. For samples with a thickness of 3 mm the best results were achieved by increasing the speed by 30 %, decrease the rate should be compared with the economy of the process to reduce surface roughness. For changes in the gas pressure was achieved the best values at a pressure increase of 30 %. When you change the performance of the best results are achieved by setting 100–90 % capacity.
ELECTRON BEAM WELDING OF HETEROGENEOUS WELDS OF Ti/Al ALLOYS
Havlík, Petr ; Dřímal, Daniel (referee) ; Schwarz,, Drahomír (referee) ; Foret, Rudolf (advisor)
The problematics of weldability of heterogeneous welds of aluminium and titanium alloys produced by electron beam welding is discussed in this work. Homogenous welds of selected alloys were analyzed in the first stage. Welding of these materials relates to formation of intermetallic phases at the interface of base materials due to differences in physical, chemical and metallurgical properties of base materials. One of the prerequisites for producing high quality weld joints is to find optimal process parameters. The influence of selected process parameters to integrity, structure and mechanical properties of heterogeneous Al/Ti joints is evaluated.
Deposition of thin metal layers by vacuum magnetron sputtering device
Rogozhnikova, Mariia ; Hylský, Josef (referee) ; Strachala, Dávid (advisor)
This bachelor’s thesis is focused on description of magnetron sputtering device NP 12 for the thin metal layers forming. In this work is mentioned the issue of metal layers, is given an overview of the methods of their forming and description of magnetron sputtering. Practical part of this thesis describes creation of the NP 12 sputtering device controlling instructions and creation of ten working samples. Copper, aluminum, and titanium layers were sputtered on a glass and silicon substrate bases. An appropriate processing parameters have been defined experimentally. The conclusion of this final work gives analyzes of surface flatness and purity of the sputtered layers using AFM and SEM measurements methods.
Mechanical properties of materials prepared by SLM process
Doubrava, Marek ; Válka, Libor (referee) ; Pantělejev, Libor (advisor)
The diploma thesis deals with the selection of process parameters used for manufacturing of high-strenth materials using SLM technology. The feedstock material was powder with a chemical composition according to standard DIN X3NiCoMoTi 18-9-5. Influence of change in process parameters on mechanical properties was examined by hardness tests and tensile tests. Metallographic and fractographic analysis were conducted with an aim to understand mechanisms of failure present in this type of material. Selection of optimal process parameters was based on the analysis of mechanical properties of manufactured samples. Possible future steps related to the improvement of the process were proposed. Results of this experiment were compared with literature regarding parts produced by SLM technology and conventional methods.
Process Parameters Development for Producing of Lattice Structures Using 3D Metal Printing
Moravčik, Jaroslav ; Koutný, Daniel (referee) ; Vrána, Radek (advisor)
Selective laser melting (SLM) belongs to additive technologies. Progressive adding of layers of material powder and creating the structure with laser beam allows to create components with complex shapes, for example microstructures. This thesis explores potential of new printing strategies, which could lead to good melting of printed component and reaching to better structure without porosities. Based on analysis of actual state, software for calculation of laser trajectory was made with use of new printing strategy. Also, process parameters obtained from technical articles and from experiments made on Institute of Machine and Industrial Design on Faculty of Mechanical Engineering BUT in Brno were compared. This comparison led to suggestion of test set of components with new parameters and strategies. This set could lead to new researches in this issue.
Development of WAAM process parameters for thin-walled components made of magnesium alloy AZ61
Šváb, Čeněk ; Němeček, Stanislav (referee) ; Slavíček, Jakub (advisor)
The thesis deals with the development of WAAM (Wire Arc Additive Manufacturing) process parameters for thin-walled parts made of magnesium alloy AZ61. The aim of the thesis is to find suitable process parameters and describe their influences on the welding process. To achieve this goal, these parameters were experimentally tested. It was found that the parameter of boost phase current and the duration of its application have the highest influence on the weld geometry. The stability of the welding process was then influenced by the electrode feed rate during the boost and burn phases. Based on these results, a final set of parameters was created, which successfully welded a thin-walled part composed of 50 layers and reaching a height of 130 mm.
Influence of Process Parameters and Heat Treatment on the Structure and Properties of Cold Spray Method
Lindner, Patrik ; Řehořek, Lukáš (referee) ; Hutařová, Simona (advisor)
The bachelor thesis is a research of the state of knowledge focused on Cold spray technology and process parameters affecting the properties of coating, such as pressure, temperature, nozzle speed, sequence of individual layers, size of powder and others. This technology uses the kinetic energy of the impact of particles on the substrate. The main advantage of this method is possibility of forming a coating of large thicknesses (in millimeters) without oxides, with relatively low porosity and favourable mechanical properties. Aim of this work is to get acquainted with the Cold spray technology and the influence of process parameters on the quality of the spray. The influence of process parameters on properties is also demonstrated by own experimental results.

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