|
|
Compared HAZ the methods of welding TIG, MAG and CMT
Šoulák, Petr ; Sigmund, Marian (referee) ; Kubíček, Jaroslav (advisor)
The bachelor thesis was to compare the HAZ size for the TIG, MAG and CMT methods. The welded materials were low carbon steel and austenitic stainless steel. Samples of 250x50 mm size and 2 mm thick were welded with butt weld without a gap. In the first part of experiment, samples were welded at the same welding speed. The second part concerned only CMT, where the optimal welding speed was used. For selected samples, the HAZ size was measured and compared in macroscopic images.
|
|
|
Welding technology of the "fuel cell" component
Vaculka, Jakub ; Dohnal, Ivo (referee) ; Kubíček, Jaroslav (advisor)
The project aimed at the selection of the optimal welding method for a „fuel cell“ component in terms of the VN-Ú Ltd engineering company. The goal is to compare the methods available in VN-Ú, that is: TIG, MIG/MAG and CMT. It is necessary to analyze the specifics of each of the technologies and the operation conditions which the component will be exposed to. For the comparison of the methods, non-destructive testing of the components, as well as destructive tests of the produced samples have been used. The economic evaluation has been used to compare the costs of different welding methods of the components and to assess the potential investments in CMT device that has only been leased by VN-U so far.
|
|
|
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.
|
|
|
New aspects of MIG/MAG welding
Minich, Marek ; Hála, Michal (referee) ; Kubíček, Jaroslav (advisor)
The thesis discusses the welding method MIG/MAG and the methods based on it. These methods are CMT and CMT Advanced which are currently still being improved. In the work are described their principles, benefits, uses and devices that allow welding by those methods. The thesis deals with the issue of a joint of steel and aluminum which is no longer an obstacle in welding due to CMT. This is a huge benefit especially for the automotive and aerospace industries, for which the solid and fast connection between steel and aluminum is a very desired matter. Further, there are welds of thin sheets described and discussed and also a list of wide range of practical uses for these welding methods.
|
|
|
Welding parameters optimalization of robotic welding for car industry
Soprunenko, Valeriia ; Mrňa, Libor (referee) ; Sigmund, Marian (advisor)
Thesis deals with individual technology of new welding processes "specifically FRONIUS TPSi". The greatest emphasis is on welding technology, especially on the differences between the individual methods. The experimental part of the thesis is focused on finding suitable parameters for welding filled welds.Everythingwith respect to required welds quality welded by robotic welding. The samples were evaluated in terms of penetration depth, amount of heat introduced and the number of defects.
|
|
|
Design of oscillating head for surface welding of Inconel 625
Franc, Tadeáš ; Slaný, Martin (referee) ; Zouhar, Jan (advisor)
This diploma thesis deals with the structural design and production of a oscillating head for surface welding of a protective layer of Inconel® 625 superalloy on membrane walls. The design is preceded by a research for possible variants of the solution. Of the two designs, one was successfully manufactured and assembled, and incentives for future improvements were set. For easy optimization and testing of the device, an oscillating motion program was created in the LinMoT Talk 6.9 software. The production costs for the manufactured equipment were then calculated and the recommended selling price was determined, based on a general calculation formula. The result of the project is a functional device, a proposal for its control and a technical - economic evaluation of the production process.
|
|
|
Design of equipment for welding head path correction
Benáček, Filip ; Jaroš, Aleš (referee) ; Slaný, Martin (advisor)
The work presents the problem of welding of membrane walls intended for application in power boilers. Furthermore, the use of the MIG/MAG method for welding and the advantages of using the CMT method. An innovation has been made for the welding process in the form of laser scanning of the surface and subsequent use of the data to correct the welding head. This led to the automation of the whole process. Because of the necessary testing of the laser scanner function, a test structure was designed and constructed. It was necessary to consider the appropriate wall scanning strategy and subsequent data processing in terms of the overall manufacturing process. The software designed to evaluate the scanned profile placed a point using a suitable tool on the scanned profile. The set of points was further filtered for a smoother resulting path formed by these points. The resulting points were fed to the output signal from the laser device to correct the path of the welding head. Both the welding and the surface scanning will be done simultaneously, so the settings for the laser scanner were created and stored in the internal unit of the device. This allows the laser to operate without connecting to a computer.
|
|
|
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.
|
|
|
Analysis of Inconel 625 weld layer produced by MIG-CMT
Chrást, Daniel ; Slováček, Marek (referee) ; Kubíček, Jaroslav (advisor)
Návary z materiálu Inconel 625 na základní materiál 16Mo3 slouží v energetickém průmyslu u spaloven odpadu pro zvýšení životnosti membránových stěn. Návarové housenky jsou vytvořeny pomocí metody MIG-CMT. Byly provedeny analýzy makrostruktury a mikrostruktury za použití SEM mikroskopu Apreo 2, dále byla provedena analýza chemické složení návarové housenky za použití OES spektrometru ISpark. Nakonec byly provedeny analýzy vybraných mechanických vlastností, konkrétně mikrotvrdost a tažnost.
|
|
|
Vehicle Re-Identification Using Vision Transformers
Jelínek, Zdeněk ; Hradiš, Michal (referee) ; Špaňhel, Jakub (advisor)
The main objective of this thesis was to investigate the potential of vision transformers in vehicle re-identification. Convolutional neural networks have so far dominated this area of computer vision. In total, two models have been tested - TransReID and CMT. TransReID is a model based purely on vision transformers and was created specifically for vehicle re-identification. The main part of the experiments with this model was devoted to the use of key points on the vehicle. With proper extraction of the regions around the key points and the use of post-processing, I achieved state-of-the-art results. The CMT model is a combination of convolutional networks and transformers that was not designed for vehicle re-identification. I modified the model and conducted extensive experiments with it to obtain the best configuration for vehicle re-identification. I evaluated the models on the standard datasets VeRi-776, VehicleID, CityFlowV2-ReID and CarsReId74k and compared with state-of-the-art models. With the CMT model, I achieved the best result of 0.860 on the mAP metric on the VeRi-776 dataset and the best result of 97.6% on the Rank5 metric on the VehicleID dataset.
|
guest ::
