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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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Weldability of steels for the manufacture of bicycle frames
Grim, Robert ; Richter, Tomáš (referee) ; Vaněk, Mojmír (advisor)
This thesis is focused on steel materials used in bicycle frame manufacturing. The alloys are analysed based on their mechanical properties as well as their weldability. Steel materials are divided into three groups corresponding to the foremost frame manufacturers. Alloys with trade names are paired with equivalent normalized materials selected according to their chemical composition. The weldability of individual steels is addressed in several chapters sorted by materials’ mechanical properties and structure. The work further explains why TIG welding of frames is preferred and what the method’s main advantages are.
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Use of the preheating by electric arc during laser welding of steels with higher carbon content
Mach, Martin ; Sigmund, Marian (referee) ; Mrňa, Libor (advisor)
The thesis is focused on the study of the use of electric arc preheating, in this case source WIG, during laser welding of steel with a higher carbon content, specifically for this work steel 1.1191 thickness 2 mm. Based on the calculation of the carbon equivalent, the preheating was determined to 208 °C. The welding parameters were selected on the basis of the first experiments. In the experimental section, the samples were welded with laser with preheating using a source WIG, which were then made to a tensile test, Vickers microhardness, macrostructure and microstructure. By using a second heat source, the heat-affected area of the samples was expanded. Samples that cracked in the middle of the weld during the tensile test were heat influenced by cutting samples. The remaining samples was broken in the base material, thus the weld produced was of good quality. Combination of laser welding with WIG electric arc preheating is a very productive method over conventional methods and one of the few pre-heating solutions for laser welding. These are the initial experiments for the use of the WIG arc for preheating in laser welding, to be followed by further research, mainly for the automotive industry.
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Design of the trough with respect to hygienic requirements
Venc, Jan ; Staněk, Vojtěch (referee) ; Podaný, Kamil (advisor)
The thesis presents a proposal of a hygienic trough. The trough is made by the company ACO Industries k.s. from stainless steel 17 349 of thickness 1,5 mm. Literary studie is focused on respect to hygienic requirements, which are defined by EHEDG. The trough was valorized and necessary adjustments were proposed to meet the conditions. Based on proposed profile and on the main volume makes custom production, was selected Bending as the most favourable technology for construction and WIG method for welding.
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Influence of shape of the electrode to weld pool
Hrádek, Jan ; Vaněk, Mojmír (referee) ; Kubíček, Jaroslav (advisor)
The project is focused on welding of TIG method. In this method is used non-melting tungsten electrode, which can have different top angles. In different literature there are different opinions about how angle influence weld pool. It was sharpen six different angles of electrode with whom was done welds on carbon steel S235JR and on austenitic corrosion resistant steel x5CrNi1810. The evaluation was done with help of chart where on the axis x is angle of electrode and on axis y are depth and width weld in millimiters. The result of this project was the prove of opinion that with more sharper angle of electrode is depth of weld smaller and width bigger.
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Renovation of tools steels for cold forming
Hrabina, Martin ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
Master’s thesis “Revovation of tools steels for cold forming“ characterizes wear resistant welds for tool steels. The thesis is dividend into two main chapters. The first chapter of the thesis is focused on the theory of wear for cold work steels. The theory is combined with an experimental chapter. The experimental part describes particular materials and technology for welding. The conclusion of the thesis is evaluated results of test for mentioned technology and welding conditions.
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Everyday fashion show
Rémanová, Jana ; Šagát, Petr (referee) ; Ruller, Tomáš (advisor)
Work is dealing with the problems of unusual clothing and conflict with surroundings. The work includes research of what is regarded as weird, extravagant and alternative in everyday fashion, but also designs of outfits inspired by research made by questionnaires and finally realization of artistic performances in public places. The result of the project is information obtained from the research of one hundred respondents. Furthermore, a series of ten "costumes", which show the stimuli obtained from previous research from selected questionnaires. Each model is an example of the stereotype of what was found to be eccentric in dress. In these models, a performance was subsequently performed in public. All individual phases of project creation are presented as a whole and presented as a bachelor's thesis.
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The effectiveness of welding on furnace structures.
Rousová, Michaela ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
This diploma thesis is resolving all the possibilities of enhancing the efficiency of furnace structures welding. Small batch production does not offer many possibilities for implementing mechanization or automation. On the other hand, when using a big batch production, efficiency can be enhanced by means of a robotic workstation. When the production batch is big enough, we will see a costs save after a short time, mainly in labor costs. This means the return of investments will be in short time period. In the LAC company there are three types of products made. At laboratory furnaces the efficiency can be enhance by using fixtures. At other standard and atypical furnaces is very difficult to design fixtures or positioners because of their different sizes. Big complication can be also a company location on second floor. The most suitable product regarding to welding efficiency enhancement is big batch production of heaters. For this type the welding time can be shortened by means of a robotic workstation.
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LaserHybrid utilization in welding and brazing
Labaj, Petr ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
LABAJ Petr: LaserHybrid utilization in welding and brazing The thesis deals with the basic knowledge of LaserHybrid welding, which is a combination of laser welding, and arc welding. There is also mentioned the use of shielding gas, which has a major impact on the entire welding process. Other part deals with the practical use of the welding method, it analyses the differences in diverse applications according to an industry sector, a type of used material and especially their advantages and disadvantages. LaserHybrid is a welding technology, which has a huge potential to cause a revolution in the field of welding. Its characteristics such as efficiency, quality and accuracy with which LaserHybrid systems operate are highly required. An example is the shipping industry, where was achieved a cut in production times and substantial positive economic outcome.
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Everyday fashion show
Rémanová, Jana ; Šagát, Petr (referee) ; Ruller, Tomáš (advisor)
Work is dealing with the problems of unusual clothing and conflict with surroundings. The work includes research of what is regarded as weird, extravagant and alternative in everyday fashion, but also designs of outfits inspired by research made by questionnaires and finally realization of artistic performances in public places. The result of the project is information obtained from the research of one hundred respondents. Furthermore, a series of ten "costumes", which show the stimuli obtained from previous research from selected questionnaires. Each model is an example of the stereotype of what was found to be eccentric in dress. In these models, a performance was subsequently performed in public. All individual phases of project creation are presented as a whole and presented as a bachelor's thesis.
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