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Welding inverter
Lizúch, Ján ; Vorel, Pavel (referee) ; Martiš, Jan (advisor)
The aim of a masters thesis is to design components, circuits and to build welding power source. Description and technological process of welding, arc characteristic and welding methods requirements are included in a first part of the thesis. Switching mode power supply topologies are characterized in a next part of the thesis. At the end of a theoretical part, the parameters of welding power source are determined. Its design is described in the next parts of the thesis where calculations and design process of electrical part is described. There are also schematics of circuits shown. In each power part is power dissipation calculated, what is needed to design cooling. Practical build and tests of welding power source are described in the last part of thesis. Measured waveforms and thermal camera images during load test are included in the last part as well
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Porosity during welding aluminous alloys
Hájková, Alena ; Daněk, Ladislav (referee) ; Sigmund, Marian (advisor)
This thesis deals with the problem of occurrence of porosity in aluminous alloys and the methods of their repair in the company IFE. Theoretical part is aimed on the current state of porosity and the ways in which the be pores can be repaired. Used technologies of repairs are TIG welding and cementing. The practical part consists of experiment in which is used a method of cementing on specific part.
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The design of table belt sander
Šimčík, Jaroslav ; Pavlík, Jan (referee) ; Bradáč, František (advisor)
Jaroslav Simcik The design of table belt sander BP, Institute of production machines, systems and robotíce, 2008, p. 41, fig.19, appendices 15 This bachelor´s thesis belongs in the domain of wood-working engineering with a direction on a construction of a belt sander. The surface speed of a abrasive belt has to be 11 metre per second.
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Exposure to Nanoparticles in Work Environment
Köbölová, Klaudia ; Mikuška, Pavel (referee) ; Adamec, Vladimír (advisor)
Outside to the wide range of potential benefits, the use of nanomaterials can endanger human health and the environment. This diploma thesis presents the results of pilot measurements, where the exposure of nanoparticles was monitored. Based on a literature research a suitable method for measurement was the three-stage OECD model. Based on this model, measurements were performed in three welding workplaces, where nanoparticles are produced incidentally. The measurement consisted of collecting information and measuring the concentration of nanoparticles in the workplace, where data collection was focused only on inhalation exposure. During welding, 0.3 m size particles are produced and their concentration is strongly influenced by the welding material, type of welding and suction. The particles are amorphous in terms of morphology and contain manganese, iron and silicon, which can cause neurodegenerative diseases. Furthermore, the results indicate the importance of monitoring oral exposure.
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Structual welding of aluminium alloy
Blahák, Petr ; Hála, Michal (referee) ; Kubíček, Jaroslav (advisor)
The project elaborated in frame of engineering studies branch 2303R002 presents a project that contains welding a structure made of aluminium alloy. There were two usable methods selected, based on literal study of welding aluminium alloys, TIG welding and friction welding, and these were compared with alternative methods of joining, hard soldering and bonding. A work procedure was made for TIG method, soldering and bonding and four experimental joins were made thereafter. Project compares these methods mainly in economical way, also in way of technological difficulties and in way of observance the strength of base materials. Project also deals with problems with lowering strength of base material in heat affected area, burn out of thin material, tendency of aluminium to fill with hydrogen, quick oxidation and consequent hard surface layer emerging on the aluminium.
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Manual versus orbital GTAW piping welding
Hofbauer, Jan ; Kubíček, Jaroslav (referee) ; Sigmund, Marian (advisor)
In thesis are compared options of stainless steel piping welding, orbital and manual version of method GTAW and GMAW. At the beginning, these methods are described theoretically and after that there are described materials used for fabrication two test welds on austenitic steel piping of diameter 168 mm. The first weld was made by orbital method GTAW, the second one by manual method GMAW. Next, these two welds are compared based on defects, welding parameters and width of heat affected area. The conclusion is that both welds are defect-free and because of economical aspects is better to use orbital GMAW method for this diameter of piping.
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Laser brazing in the car industry
Podstavek, Michal ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
The project elaborated in frame of engineering studies of the subject M-STG Mechanical Engineering describes elementary methods of joining in the automotive industry. Moreover, it inquires into optimization of laser brazing on the back cover ŠKODA Superb. During the optimization of the process six samples were designed, and the adjustment of the brazing parameters were performed. Consequently, the samples were evaluated by tensile and metallographic tests. Finally, EDS analysis was performed and visual assessment as well.
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New aspects of MIG/MAG welding
Týn, Zbyněk ; Daněk, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
This bachelor thesis is focused on the latest welding technology MIG / MAG. Between which such us method of Cold Metal Transfer or Advanced CMT. These new techniques are mainly used for welding thin sheets. They integrate gradually into the connecting of various types materials and also bulky welded structures. All of this is demonstrated thanks to the management and control of the welding process.
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Welding problems of the „press chamber“ component
Čermák, Petr ; Dohnal, Ivo (referee) ; Kubíček, Jaroslav (advisor)
Petr Čermák: Welding problems of the "press chamber" component The goal of this work is to produce the "press chamber" component of a food industry machine and selection of a suitable arc welding method, a base and a filler material. Practical part of this work includes technological design of a weldment production process considering all the know-how concerning welding technology, heating process of a stainless steel and a weld quality testing. Especial emphasis is put on analyzing of deformations and residual stresses during welding and taking countermeasures to reduce these undesired defects in the "press chamber" weldment made of high alloy austenitic steel. The final output is the "press chamber" component and a welding jig design reducing occurrence of the undesired deformations or residual stresses.
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