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Mechanical properties of optical thin films
Tomáštík, J. ; Čtvrtlík, R. ; Šebestová, Hana ; Schovánek, Petr ; Jankůj, J. ; Hrabovský, Miroslav
Mechanical properties of optical thin films and coatings are very important for their reliability, because they are often exposed to rough conditions in service. Mechanical attributes of films, that determine their behavior, are in the center of interest. In this paper, mechanical properties of optical thin films deposited on various types of glass substrates were examined. Assessment of such properties was performed using instrumented nanoindentation (hardness, elastic modulus, elastic and plastic work done by indentation) and scratch test (critical loads corresponding to the onset of specific failure). The failure modes of thin films were discussed.
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Laser scanning confocal microscopy for 3D surface mapping
Lapšanská, Hana ; Schovánek, Petr
This contribution introduces a modern microscopic method and shows possible measurements and analysis of wire saw machined glass pieces. The main objective of realized measurements is to identify possible defects and its depth to propose eventual additional treatment. We are looking for the optimal technological procedure of grooved glass stick-on supports preparation. Such supports are used for the very thin accurate optical components production which is executed in our workshops and laboratories. Surface quality of the support significantly influences the quality of produced optical components.
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FEM simulation of thermal differences in semi finished glass pieces during the cooling
Havelková, Martina ; Schovánek, Petr
Semi finished glass pieces are moulded in the furnace to template forms not only to fit their shape but also to reduce internal stresses. Thermal differences are unwanted and have to be minimized in the cooling procedure of the glass pieces. Simulations of various types and sizes of shaping forms and complex model cooling were accomplished. The aim of these simulations was to optimise geometric parameters, clamping conditions and material of the form, so that thermal differences at glass are minimized during the cooling.
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Numerical modelling of the glass shaping forms cooling
Havelková, Martina ; Schovánek, Petr
The purpose of heat treatment of semi finished glass pieces in shaping forms is not only to fit their shape but also to reduce internal stresses. Thermal differences are unwanted and have to be eliminated in the cooling procedure of the glass pieces. Simulations of different types and sizes of shaping forms and complex model cooling were accomplished. The aim of these simulations was to optimise geometrical parameters, clamping conditions and material of the form, so that thermal differences at glass or glass – form interface are minimized during the cooling.
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Nová měřící metoda tvaru konkávních zrcadel na principu digitálního zpracování Hartmanova testu
Pech, Miroslav ; Mandát, Dušan ; Hrabovský, Miroslav ; Schovánek, Petr
V tomto článku je prezentován princip speciálního Hartmannova testu, což je metoda, která je použitelná pro bezkontaktní měření tvaru vlnoploch a tedy i odrazných ploch. Popisovaná metoda je v zásadě klasický Hartmannův test, ale je zde použito digitální zpracování dat a navíc místo binární masky je zde použit transparentní prostorový modulátor. Metoda byla vyvinuta pro kontrolu reflexních ploch segmentů zrcadla, které se použijí na fluorescenčních teleskopech observatoře Pierre Auger [1]. Tyto segmenty jsou z důvodu redukce hmotnosti velmi tenké, tento fakt ovšem zapříčiňuje nestabilitu tvaru při výrobě. Tato metoda objektivně určí tvar zrcadla a odchylku od ideálního sférického tvaru a to s mikrometrovou přesností.
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