|
| |
|
|
Research of a Cutting Tool with a Diamond Active Part
Trčka, Tomáš ; Mrkvica, Ivan (referee) ; Chladil, Josef (referee) ; Polzer, Aleš (advisor)
The submitted dissertation is focused on research in the field of milling tools with a diamond active part when machining one of the difficult-to-machine materials (Ti-6Al-4V). The first chapters are dealing with a theoretical analysis of a given workpiece material and polycrystalline diamond (PCD) as a super-cutting material. One of the theoretical chapters is also focused on tool sharpening technologies, for which the hardness of a diamond is no longer a crucial factor. The main part of the dissertation is the design, construction and production of tools taking into account the technological design, along with the application of modern trends and technologies enabling innovation and progressive design – from the perspective of macro/micro tool geometry and insert sharpening technology. The research was focused on the application of own inserts on the insert rake face and specific sharpening technologies EDMG, WEDM and LASER. One modification of the face of the PCD insert with a laser was subsequently applied to prototype circle segment end mill. Detailed analysis of manufactured tools and workpiece material was performed by electron, optical and digital microscopy. The measured parameters in the subsequent analysis of the machining process were force loading, tool wear, temperature measurement using a thermal imaging camera and analysis of the machined surface in the form of microhardness and roughness measurements.
|
|
|
Design of an engraving LED laser
Kasík, Martin ; Sliwková, Petra (referee) ; Dvořáková, Jana (advisor)
This thesis is focused on the search of unconventional machining methods, especially on the technology of laser beam machining. It deals with the area of laser cutting and engraving and examines the influence of individual technological parameters on the given process. Furthermore, there is proposal of design of hobby LED engraving machine, its supporting structure, HW and other electronic components. The prototype of the device is physically assembled and its functionality is verified in the form of several engraving tests of raster and vector formats of graphic materials, and some several shape cuts are made also. The technical evaluation of the assembled equipment, evaluation of tests performed and cost calculation is part of the work too.
|
|
|
Laser cleaning of technical materials
Čermák, Filip ; Joska, Zdeněk (referee) ; Sedlák, Josef (advisor)
This thesis deals with the issue of the effect of laser cleaning on the surface of the base material, respectively on its surface texture. The theoretical part of the thesis is focused on the characteristics of laser technologies, an overview of surface cleaning methods in the field of mechanical engineering and the introduction of the company ŽLUTÉ LASERY s.r.o., that helped to create and process the assigned topic. In the practical part focused on the experiment is discussed the choice of materials, production of samples, selection of types of impurities and their application to designated areas. The main part is a description of the laser cleaning process, roughness measurement and statistical evaluation of the investigated surface roughness parameters (Ra, Rz, Rp, Rv, RSm, RPc, Sa, Sz, Sp, Sv, Spd and Spc). In the end, the processed results are evaluated and presented.
|
|
|
Active stereo vision
Doležal, Milan ; Richter, Miloslav (referee) ; Janáková, Ilona (advisor)
This thesis deals with active stereo method for measurement of objects with transparent layer. In theoretical part of this thesis is described method of active triangulation and method of active stereo. After that, there is research of articles focused on transparent layer in optical measurement. Next chapters deal proposition of measuring system, it's parameters, calibration, procedure and evaluation of measurement. MATLAB was selected as programming platform.
|
|
| |
|
|
Physics of medical devices
Čečák, Michal ; Lustigová, Zdena (advisor) ; Rotter, Miloš (referee)
My bachelor thesis deals with medical devices. Specially operates with four instruments, that people are familiar with them. The text is designed for teachers at primary and secondary school. Thesis includes also three worksheets. At the end of each are also links to website that we could find some new information about issues studies.
|
|
|
Selection of femtosecond laser pulses
Bažíková, Sára ; Trojánek, František (advisor) ; Zázvorka, Jakub (referee)
Construction of the laser is one of the most important physical advances of modern times. Its use in practice is extremely common and desirable, therefore, it is necessary to push the boundaries of possibilities of this technique still further. Lasers generating ultrashort pulses are widely used in material research for the study of nonlinear effects and ultrafast processes. These lasers have a high repetition rate, which must be reduced for some applications. In this thesis we used femtosecond titanium -sapphire laser from Spectra Physics, whose repetition rate is 80 MHz. The aim of this thesis is to reduce this frequency by using a pulse selector. The key mechanism that utilizes the pulse selector is an acoustooptic modulator that is based on the principle of Bragg diffraction and it is able to select pulses with a frequency of 1 Hz-4 MHz. The end of thesis is measurement of the properties of this selector and its optimization.
|
|
| |
|
|
Laser absorption spectroscopy
Vyhlídka, Štěpán ; Plašil, Radek (advisor) ; Hrubý, Vojtěch (referee)
Study of recombination of molecular ionts in cold plasma plays a key role in our understanding of chemical kinetics in interstellar space or in upper layers of planetar atmospheres. Various metods are used for its study of which important part is laser absorption spectroscopy. Concentration or temperature of measured ionts can be found from their absorption spectra. In the presented work two spectroscopic techniques are briefly introduced - Cavity ringdown spectroscopy and Laser induced reaction technique. Main me- chanisms for spectral linewidth broadening are described and from absorption spectra of H+ 3 and N+ 2 ionts measured by above-mentioned techniques their kine- tic temperature is discovered. Because it is affected by spectral width of applied laser diodes, a part of this work also deals with description of its measurement by self-heterodyne method or Fabry-Pérot interferometer. The spectral width is found for infrared diode DFB laser. 1
|
guest ::
