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Unconventional methods of material cutting
Rusz, Radek ; Mrňa, Libor (referee) ; Podaný, Kamil (advisor)
The bachelor thesis contents literary study of a unconventional methods of material cutting. Work is focused on cutting technology of a water jet, plasma, laser, ultrasound and electron beam. Each method is explained in terms of physical principle and application in industry. Also, there is the technological equipment for the various methods, including evaluation of their parameters. The work is also a comparison of all methods in terms of productivity and material processing quality, assessment their advantages and disadvantages, and suitability for small- or large volume production.
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Unconventional methods of material cutting
Kulenda, Martin ; Mrňa, Libor (referee) ; Podaný, Kamil (advisor)
The present bachelor thesis summarizes the findings of unconventional methods of materials cutting. The thesis is only concerned with the most common and most appropriate methods used in practice. The described methods include cutting by laser, plasma, water jet, electron beam and ultrasound. For each of these methods, the principle of current technologies and technological equipment used for materials cutting in industrial practice is described. This thesis compares the individual methods in terms of their advantages and disadvantages when cutting different types of materials and also the appropriateness of the use of such methods in small or large series production.
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Electron vortex beam
Müllerová, Ilona ; Řiháček, Tomáš
Vortex electromagnetic waves contain a phase singularity along their propagation direction and are formed by the spiralling wave fronts that give rise to angular momentum in that direction. Vortex photon beams are widely used optical tweezers to manipulate micrometre-sized perticles, as optical micro motors etc.
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Analysis of electron current instability in E-beam writer
Bok, Jan ; Horáček, Miroslav ; Král, Stanislav ; Kolařík, Vladimír ; Matějka, František
The electron beam writer Tesla BS600 works with a thermal-field electron emitter, fixed electron energy of 15 keV and a rectangular shaped variable-size electron beam. The size of the shaped beam (stamp) can be set from 50 to 6300 nm in standard mode and from 16 to 2100 nm in high-resolution mode. The basic increment of the stamp size is 50 nm, resp. 16 nm. Electron current density inhomogeneity and long-term instability in stamps can have negative impact on the exposure quality. Therefore, we focused on a study of the current time instability. The current density in variously sized stamps was measured by a picoammeter and a PIN diode video channel as a function of time. We analyzed short-term and long-term current instabilities using filtering techniques, as well as the Fourier analysis. Based on the results, we could be able to find reasons of the current instabilities and to propose improvements to achieve higher exposure quality.
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Electron beam cutting of non-metals
Dupák, Libor
Various materials are difficult to cut or drill, e.g. due to their mechanical properties (hardness, fragility). Also, sometimes the required hole shape and dimensions may be difficult to obtain by mechanical machining or the efficiency of such process is low. Electron beam machining is one way to overcome these issue. It is based on the melting and evaporation of the material by the intense electron beam. The presented experiments were performed on the desktop electron beam welder MEBW-60/2, developed at the Institute of Scientific Instruments AS CR, v.v.i. at Brno. It is also manufactured and sold by the Focus GmbH company under licence. In the following experiments, several sets of grooves were prepared, both in quartz glass and AI2O3 ceramics, to find out the influence of various beam parameters on groove dimensions. The experimental conditions were as follows: acceleration voltage 50 kV, beam current 0.1-1 mA, machining speed 2.5-50 mnvs'1.
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Jednoduchá numerická simulace vnitřní struktury částicového testu
Bartušek, Karel ; Fiala, P.
The basic configuration of the electron beam was verified in Institute of Scientific Instruments Academy of Sciences of the Czech Republic experimentally. We prepared the numerical model which is based on the particle theory. Actually, it respects classical Electrodynamics Material Wave Theory (MWT). Numerical results were evaluated. The second model was prepared in respect to theory of wave packet (Louis de Broglie) and solved again. Results of both models were the same in their quality, we evaluated electric field intensity E on the electron impact area, and they corresponded with results from experiments.
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Micro-machining by an electron beam
Zobač, Martin
The work deals with problems of removing material with an intensive electron beam (EB) in vacuum. The main goal is study of the interaction of EB with metallic and possibly non-metallic materials. An undividable part of the work is a preparation of an experimental device, its experimental parts and the electron gun. It will be necessary to create a unique electronics, especially a HV source enabling impulse operation of the electron gun.
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Dispersion and detection of signal electrons in environmental SEM
Romanovský, V. ; Neděla, Vilém ; Hutař, O.
The environmental scanning microscope is based on convenient adaptation of classical SEM employing the focused primary electron beam. For the proper function of the electron gun the pressure in this part of the microscopemust be less than 10.sup.-3./sup. Pa. The working pressure in the specimen chamber in environmental microscope reaches the order of hundreds of Pa.Therefore, the effective vacuum separation of these two parts is necessary. This can be obtained by the use of two or more apertures limiting the gas flow. It is also necessary to evacuate the space between the apertures by a vacuum pump of a high pumping speed. The increasing of pressure in the specimen chamber brings some difficulties, especially the dispersion of signal electrons by the influence of interaction with the gaseous environment.
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