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Possibilities of regulation of stored heat - experimental verification
Mášová, Pavla ; Kubíček, Jaroslav (referee) ; Daněk, Ladislav (advisor)
This diploma thesis elaborated within the Manufacturing Technology Master´s study program considers various possibilities of welding which can regulate the amount of inputted heat into the welded joint. For experimental testing, material X2CrTi12 (ferritic stainless steel) was chosen, welded by means of methods suitable for the material. Welding methods included TIG, plasma, and laser. Further possibilities of heat input are suggested, such as pulse welding, Rapid, Fast Root, Surface Tension Transfer, Cold Metal Transfer, ColdArc, and Wise. The aim of the experiment is to compare the amount of heat input and its effect on particle growth and hardness.
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Unconventional methods of welding of wrought magnesium alloys
Klimčáková, Kateřina ; Mrňa, Libor (referee) ; Doležal, Pavel (advisor)
Master's thesis deals with consideration possibility of conventional and unconvetional welding methods of wrought magnesium alloys. Methods of Friction Stir Welding, Pulsed Nd:YAG laser and Continuous Fiber laser was used to join magnesium alloy sheets AZ31, AZ61, ZE10 and ZE41. For studying influence of processing parameters on microstructure and mechanical properties were used methods of light microscopy, scanning electron microscopy, tensile tests and microhardness measurements. The results of tensile tests show that from the point of view of keeping ultimate tensile strength is the best methods for welding magnesium alloys Friction Stir Welding. Compared with Nd:YAG laser, fiber laser give better properties of welds. From comparing microstructure and mechanical properties . It wasn't found publications about Friction Stir Welding of magnesium ZE alloys or about FSW sheets with thickness only 0,8 mm and 1,6 mm.
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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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Study on dependency of the weld geometry on process parameters in laser hybrid welding of aluminum alloy
Wojnar, Michal ; Kubíček, Jaroslav (referee) ; Mrňa, Libor (advisor)
A study carried out in the bachelor 's degree in engineering technology deals with changes the geometry of the weld technologies created laserTIG . The theoretical part provides an overview of the basic characteristics and advantages of welding technology laserTIG a summary of the issues welding of aluminum alloys. The experimental part consists in the execution of fifteen test welds on a sheet of Al alloy 2024 tl . 3 mm. From the measured values of individual welds were prepared according to the depth and width of the seam TIG welding current at a constant laser power and dependence on a specific area of the weld heat input Qs. By comparing the dependencies have been demonstrated theoretical advantages of laser hybrid technology , which consist mainly of increasing the welding speed and lower heat load of the welded material. Using the laser hybrid welding for welding of aluminum alloys proven advantageous.
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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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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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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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Comparison of hand and orbital welding by TIG method
Dušek, Vojtěch ; Hála, Michal (referee) ; Kubíček, Jaroslav (advisor)
DUŠEK VOJTĚCH: Comparison of hand and orbital welding by TIG method This bachelor thesis presents a comparison of manual and orbital TIG welding. It describes the advantages and disadvantages of manual and orbital TIG welding. Mechanical properties, surface structure and heat input on the weld samples were experimentally compared. Thesis also includes technical-economic comparison of these two methods of welding.
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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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Progress of welding in shipbuilding
Urban, Václav ; Kubíček, Jaroslav (referee) ; Kovář, Petr (advisor)
This work deals with the methods of welding in shipbuilding, summarises the basic techniques used for welding of the SAW, MAG, MIG, TIG, laser, Laser-Hybrid. It describes the properties of welded material. Especially the materials HY80 and HY100. It follows from the filler materials. In particular materials Spoolarc 95 and 120. Particular emphasis is placed on the method of Laser-Hybrid, its properties and use in shipbuilding. Finally, describes the method of welding aluminium using FSW, preparation of welded surfaces and producting of sandwich panels.
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