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Measurement of roughness of the laser cutting edge by Yb-YAG laser
Dočekal, Miroslav ; Hála, Michal (referee) ; Mrňa, Libor (advisor)
The project carried out in the bachelor's degree program B - STG (“Mechanical Engineering Technology”, 2303R002), evaluates the roughness of the cutting edges of steel plates cut by laser according to the ČSN EN ISO 9013 standard. The test samples were cut by Yb - YAG laser. In total, 11 samples were measured. The samples represent three kinds of material and were cut by two ways of laser cutting; the fusion method and the oxidation method. The samples of stainless steel X10CrNi18-8 were cut by the fusion method and the remaining samples of the DC 01 steel and S235 JRG steel were cut by the oxidation method. The samples were evaluated according to the ČSN EN ISO 9013 standard. The standard evaluates the quality of cut in thermal cutting and classifies individual cuts into accuracy classes. The samples of stainless steel fall into the first and second classes of accuracy. The samples of structural steel all fall into the second class of accuracy. This classification is the outcome of the practical part of the project. The theoretical part deals with the basic principle of laser, its parts, the industrial use of lasers and the lasers most commonly used in industry. It focuses particularly on laser cutting and the parameters which affect the quality of the cut in laser cutting. The measuring of roughness and the ČSN EN ISO 9013 standard are also described.
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Manufacturing possibilities of motorcycle brake wheel
Rozum, Josef ; Dohnal, Ivo (referee) ; Podaný, Kamil (advisor)
This bachelor thesis presents a variant solution of mass production of motorcycle brake wheel. These are part of rotating component of large diameter and small thickness made up mainly of carbon steel. The thesis presents methods for the production of unconventional machining technologies and methods of molding. As appropriate variants were selected technologies of laser cutting, water jet cutting, plasma cutting, blanking and fineblanking. The individual methods are described and evaluated their suitability for production. For fineblanking method which seems to be optimal is indicated the production process.
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Measurement of roughness of the laser cutting edge
Pokorák, Milan ; Hála, Michal (referee) ; Mrňa, Libor (advisor)
This thesis primarily deals with the laser material cutting and with the subsequent evaluation of roughness of the cutting edges. The thesis is divided in two parts, the theoretical part followed by the practical one. The theoretical section is concerned with the introduction to laser technology and with the basics of roughness measurement. It contains the history of laser, its construction and its physical principle. It also deals with the description of laser types and laser technologies. An important part is about the surface texture, which includes basic terms and methods of roughness measurement. The practical section is concerned with the comparison of roughness of the cutting edges. They were measured on S235JR steel samples with the value declared in ČSN EN ISO 9013 standard. This part contains the measurement results, the measured material and also machines and devices used. The overall evaluation of the practical measurement is mentioned in the final experiment outcome evaluation.
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Measurement of roughness of the laser cutting edge
Vaculka, Jakub ; Hála, Michal (referee) ; Mrňa, Libor (advisor)
This bachelor thesis elaborated as a part of branch 2307 engineering studies describes metal laser cutting and its industrial use. The thesis consists of theoretical part and experimental part. The theoretical part describes physical and constructive principle of industrial lasers, its individual types, advantages and use. The experimental part goes into results of common quality steel oxidizing cutting. The CO2 laser from TRUMPF company was used in this experiment. Cut defect appearance and final roughness of cutting edge were the subject of evaluation. The conclusion summarizes effect of material chemical composition and cutting proces parameters on cutting results.
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Technology of Production Parts solar Panels
Midrla, Zdeněk ; Sedlák, Josef (referee) ; Osička, Karel (advisor)
This work is focused on a proposal of technological production process of components of a solar panel. The proposal of technological production process is suggested in terms production series of 9000 of pieces per year. The work also contains an analysis of construction of all components of the air separator equipment. There are suggested variants of stocks for some of the components. It also includes a selection of the most favourable variant in terms of material usability and practical aspect as well. There is an technological production process designed by the chosen varinat including of a production instructions.
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New trends of material cutting
Uttendorfská, Magdalena ; Špaček, Jindřich (referee) ; Peterková, Eva (advisor)
The thesis is focused on formation of a survey of modern methods of semi-product division in the area of forming technology. The first part of the thesis deals with material division conventional methods as cutting-off, clipping, refracting, cutting and sawing. These methods have already reached their utilization maximum. Their perfection is possible to be made e.g. by means of modern cutting materials. The next part is concentrated on material division special methods (oxygen cutting, laser, plasma and cutting by water jet) with presentation of their brief description. These methods have recorded the technology move ahead.
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Use schlieren method for displaying flow in laser technologies
Mrňa, Libor ; Pavelka, Jan
It is important to know the flow of gas protective atmosphere for the laser welding degree of protection of the weld pool from the atmosphere and for the interaction between the gas and the plasma plume rising from the keyhole. The gas flow from the nozzle during laser cutting of material has a significant impact on the quality of the final cut. In both cases the schlieren method a very useful tool for understanding the dynamics of gas flow. There were performed multiple experiments to clarify the flow of various kinds of gas (argon, helium, nitrogen) and their dynamics.
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Power Laser Technology at ISI 2013
Mrňa, Libor
The article described the activities of the ISI laser center. It was advanced diagnostics of laser welding process using frequency analysis, the development of a new type of adaptive mirrors for high power laser applications, an apparatus construction for laser hybrid laser-TIG welding, the development of new types of solar absorbers. Contract research for companies was offered.
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Institute of Scientific Instruments: An Overview Presenatation
Kolařík, Vladimír ; Zobač, Martin ; Fořt, Tomáš ; Vlček, Ivan ; Dupák, Libor ; Mikmeková, Šárka ; Mikmeková, Eliška ; Mrňa, Libor ; Horáček, Miroslav ; Sobota, Jaroslav
The aim of this contribution is to present the Institute of Scientific Instrument of the Academy of Sciences of the Czech Republic, mainly from the potential of applied research viewpoint. It covers mainly the six application fields including material study of metals and alloys, nano layer residual stress observation methods, 2 kW fibre laser, impact testing of hard coatings, e-beam welding, machining and engraving, and finally e-beam lithography. Recently achieved results as well as the new application potential are presented. Furthermore, each topic is assumed to have a separate presentation prepared in more details within this event. A brief overview follows. Scanning low energy electron microscopy (SLEEM) is increasingly becoming recognized as a valuable analytical tool in the field of materials science. The SLEEM is also used for observation of compressive stress in nano layers that leads to wrinkling and film delamination. Using the fibre laser, we can offer 3D laser welding and cutting of various type of materials and laser surface hardening too. For the hard coatings testing and evaluation of their impact resistance a new method was suggested (Dynamic Impact Wear Test). During testing the specimen is cyclically loaded by tungsten carbide ball that impacts of the coating/substrate surface. In house e-beam welding machine allows for welding, machining, engraving and other utilizations of intense electron beam. The group of micro lithography is able to prepare micro and nano structures in thin layers of metals and other materials; including the characterization of the realized structures
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