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Optimalizace parametrů laserového přetavování povrchu
Chmelíčková, Hana ; Kaňa, J. ; Hiklová, Helena ; Lapšanská, Hana ; Havelková, Martina
Laser beam with power density 102 W.mm-2 causes metal surface melting without material vaporization. Temperature gradient between melted spot centre and solid state boundary is formed, surface structure is changed. Cooling rate affects melted zone microstructure. In result, surface quality, porosity, homogenization, mechanical and chemical resistivity are improved. Laser melting parameters optimization of steel samples was made by means of pulsed solid state laser with average power 100 W. Energy, pulse length, feed speed and laser beam diameter were subsequently changed. Melted traces on steel surface were analyzed to discover microstructure and dimensions of affected zones. Result dependence on process parameters was evaluated and optimal parameters were chosen.
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Mapování povrchu pevných těles kontaktním profilometrem
Hiklová, Helena
Taylor Hobson instrument Form Talysurf Series 2 is introduced into this paper. This device is mechanical contact inductive profilometer for measuring roughness, waviness and form of solid surfaces. Owing to special electric circuitry it is able to work with extraordinary resolution and high accuracy. To get possession of more complete picture of the surface the instrument can create 3D surface topography by software controlled measuring row of parallel profiles. Measurements are analyzed via PC using the TalyMap software manufactured by Taylor Hobson Precision.
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Konstrukční úpravy dataprojektoru pro optická 3D měření
Pochmon, Michal ; Pravdová, L. ; Rössler, T.
Optical profilometric and topographic non-coherence measurements have a great use today, for example in deformation measurement, product quality control, total arthroplasty wear measurement and many others. These measurements are based on using optical structure, which is projected on the measured object and is deformed by its surface. Good projector of such optical structure is data-projector. Its imperfection is too large zoom of serial objective, so measurement of small objects is influenced by quite big measurement error. This is caused by projecting only small part of optical structure is projected on measured object and that negative influences resolution of measurement method. For the measurement of small objects is necessary replace the serial objective by objective, whom parameters allow the measurement of this object influenced by the measurement error as small as possible.
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Nová měřící metoda tvaru konkávních zrcadel na principu digitálního zpracování Hartmanova testu
Pech, Miroslav ; Mandát, Dušan ; Hrabovský, Miroslav ; Schovánek, Petr
The theory, optical, mechanical, and software design for a special Hartmann wavefront analyzer is presented. This method is applied for the non-contact method of concave mirrors shape measurements. The so-called Hartmann test is used with the digital image reading and the fast computer data evaluation. In this method a transparent spatial modulator is used instead of binary mask. Our institute Joint Laboratory of Optics produces segmented mirrors for the Pierre Auger observatory fluorescent detector [1]. We use this method as the qualitative measuring of this spherical mirror segments. These segments are unique because they are light and ultrathin. The production of mirrors is based on standard operations commonly used in the optical industry (cutting, drilling, milling, grinding and polishing), with the difference that they are extremely thin. This fact can cause segment shape instability in the production process.
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Laboratorní měření rychlosti průchodu ultrazvukových vln za trojosého stavu napjatosti
Konečný, Pavel
Measurement of the ultrasonic wave velocity on rock samples is one of the standard methods of laboratory study of geomaterials. However, the utrasonic wave velocity change due to impact of state of stress. Therefore, the measuremet is performed both in uniaxial and triaxial state of stress to study the ultrasonic wave velocity changes in the process of loading. The method of measurement in triaxial state of stress and first results are presented in this paper.
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