Microstructure of commercially pure titanium after cryogenic milling and spark Plasma sintering
Kozlík, J.; Harcuba, P.; Stráský, J.; Chráska, Tomáš; Janeček, M.
2018 - English
Commercially pure titanium was prepared by advanced powder metallurgy methods with the aim to produce the ultra-fine grained material. Cryogenic attritor milling was used as a first step to refine the microstructure at liquid argon temperatures to suppress recovery and dynamic recrystallization. Spark plasma sintering was subsequently employed to produce bulk material, exploiting its ability to achieve fully dense structure in short time and thus to reduce the grain growth. In order to understand the undergoing microstructural changes during the process, detailed investigation was performed after each preparation step. Powder morphology was changed significantly after milling, while particle fragmentation was only limited. Grain size after sintering was in micrometer scale, relatively independent of sintering conditions.
Keywords:
Cryogenic milling; Microstructure; Spark plasma sintering; Titanium
Available at various institutes of the ASCR
Microstructure of commercially pure titanium after cryogenic milling and spark Plasma sintering
Commercially pure titanium was prepared by advanced powder metallurgy methods with the aim to produce the ultra-fine grained material. Cryogenic attritor milling was used as a first step to refine the ...
Výroba optických komponent pro prototyp I
Doleček, Roman; Pintr, Pavel
2018 - Czech
Zpráva popisuje proces výroby freeform zrcadel, které jsou částí optické soustavy prototypu laserové hlavy. This report describes the process of a freeform mirrors production. Mirrors are part of optical system of the laser head prototype.
Keywords:
SPDT; freeform; laser head
Available at various institutes of the ASCR
Výroba optických komponent pro prototyp I
Zpráva popisuje proces výroby freeform zrcadel, které jsou částí optické soustavy prototypu laserové hlavy....
Opracování materiálu S-FPL53
Melich, Radek; Rail, Zdeněk; Šípová, Gabriela
2018 - Czech
Cílem práce je zvládnutí opracování materiálu S-FPL53 vzhledem ke kvalitě tvaru optického povrch a minimalizaci mikrodrsnosti povrchu. The aim of the work is mastering of S-FPL53 material machining with respect to the optical surface shape accuracy and to minimize the surface microroughness.
Keywords:
S-FPL 53 machining
Available at various institutes of the ASCR
Opracování materiálu S-FPL53
Cílem práce je zvládnutí opracování materiálu S-FPL53 vzhledem ke kvalitě tvaru optického povrch a minimalizaci mikrodrsnosti povrchu....
Thin nitride layers as permeation barriers
Veverka, Jakub; Matějíček, Jiří; Lukáč, František; Pospíšil, D.; Cvrček, L.; Nemanič, V.
2018 - English
Permeation barriers represent one of the crucial fields in materials development for thermonuclear fusion. Primary objective of the barriers is to suppress the permeation of hydrogen isotopes (mainly tritium) from future thermonuclear fusion facilities. Secondary objective is to reduce their retention in structural materials. Expected reactor conditions put high demands on the material, as well as on the final barrier quality. Key properties are tritium permeation reduction, absence of defects (especially cracks), high-temperature stability and corrossion resistance, and compatibility with structural materials (mostly ferritic-martensitic steels). Thin nitride layers, identified as promising permeation barriers, were prepared by diffusion-based nitridation and physical vapour deposition (PVD), and characterized.
Keywords:
Permeation barriers; Nitride layers; PVD coating; Permeation measurement
Available at various institutes of the ASCR
Thin nitride layers as permeation barriers
Permeation barriers represent one of the crucial fields in materials development for thermonuclear fusion. Primary objective of the barriers is to suppress the permeation of hydrogen isotopes (mainly ...
Characterization of flame sprayed abradable seal NiCrAl-bentonite coatings
Houdková, Š.; Česánek, Z.; Schubert, J.; Lukáč, František; Bystrianský, M.
2018 - English
The NiCrAl-21% Bentonite abradable coating, deposited by flame spraying, was exposed to 720°C / 1 hour air-annealing to evaluate its resistance against heat-induced changes. The SEM and XRD microstructure evaluation was done. After the air-annealing, the increase of HR15Y surface hardness was recorded and accompanied with decrease of abradability evaluated by Progressive Readability Hardness (PAH) test, although no demonstrable microstructural changes was recorded by SEM. XRD analyses evidenced the formation of nickel oxides and ordered Ni3Al phase during the air-annealing. Besides the abradable coating evaluation, this work brings the verification of the potential of PAH for scratch hardness testing. The measurement provides the results with low scatter, compared to usual surface hardness testing, and enables to distinguish between the depth of indentation in loaded and unloaded state, pointing out to the elastic/plastic deformation ratio.
Keywords:
Abradability; Abradable seal; Flame spray; NiCrAl-Bentonite
Available at various institutes of the ASCR
Characterization of flame sprayed abradable seal NiCrAl-bentonite coatings
The NiCrAl-21% Bentonite abradable coating, deposited by flame spraying, was exposed to 720°C / 1 hour air-annealing to evaluate its resistance against heat-induced changes. The SEM and XRD ...
Transport and package manual - collimator
Steiger, Lukáš; Václavík, Jan
2018 - English
The purpose of this document is to provide basic set of instructions and recommendations that allows careful transportation of the NEOSTED collimator (COL).\nBe aware that it is not purpose of this document to provide detailed description of individual parts of the COL system. If necessary all the details and proper references can be found in [AD-2]
Keywords:
collimator; handling; TOPTEC
Available at various institutes of the ASCR
Transport and package manual - collimator
The purpose of this document is to provide basic set of instructions and recommendations that allows careful transportation of the NEOSTED collimator (COL).\nBe aware that it is not purpose of this ...
Study on polishing of CaF2 plane-parallel elements
Procháska, František; Thoř, Tomáš; Šípová, Gabriela
2018 - English
Determination of technological procedure for processing of plane-parallel and plano-convex CaF2 optical elements. That includes optical polishing as well as preparation of samples for polishing, i.e. cementing and grinding.
Keywords:
CaF2 machining
Available at various institutes of the ASCR
Study on polishing of CaF2 plane-parallel elements
Determination of technological procedure for processing of plane-parallel and plano-convex CaF2 optical elements. That includes optical polishing as well as preparation of samples for polishing, i.e. ...
Oprava objektivu 160/2500 turnovské hvězdárny
Rail, Zdeněk; Melich, Zbyněk; Šrajer, Bohdan; Šípová, Gabriela; Kaucká, Iva; Franců, Helena; Melich, Radek
2018 - Czech
Tento referát přináší informace o opravě achromatického objektivu o průměru 160 mm a ohniskové vzdálenosti 2500 mm, vyrobeného v 70. letech ve Vývojové optické dílně ČSAV v Turnově. Refraktor s tímto dubletem se stal hlavním přístrojem místní hvězdárny. Spojka tohoto objektivu obsahovala šlíry a bylo ji nutné vyrobit novou This paper brings the information about repair of the achromatic objective lens of diameter 160mm and focal length 2500mm produced by the Development Optical Workshop of the ČSAV in Turnov. The refractor with this dublet has become the main telescope of a local astronomical observatory. The positive lens contained impurities – schlieren and it was necessary to produce a new lens and change it.
Keywords:
Achromatic dublet; aplanat; grinding; polishing; autocollimation test; optical aberrations
Available at various institutes of the ASCR
Oprava objektivu 160/2500 turnovské hvězdárny
Tento referát přináší informace o opravě achromatického objektivu o průměru 160 mm a ohniskové vzdálenosti 2500 mm, vyrobeného v 70. letech ve Vývojové optické dílně ČSAV v Turnově. Refraktor s tímto ...
Tmelený objektiv Steinheilova typu
Rail, Zdeněk; Franců, Helena; Ulrichová, Iva; Šípová, Gabriela; Jareš, Daniel; Kuryshev, V.; Vápenka, David
2018 - Czech
Tento referát se zabývá achromatickými dublety se vstupním členem z flintového skla. Optické řešení těchto objektivů navrhl německý fyzik Carl August Steinheil v polovině 19. století. V nedávné minulosti bylo několik těchto dubletů vyrobeno pro astronomické účely v naší dílně. V referátu popisujeme výpočet a technologický postup výroby tmeleného Steinheilova objektivu s rovinnou výstupní plochou. This paper analyses the achromatic dublets with an entrance lens of the flint glass. The objective lens of this construction were devised by German physician Carl August Steinheil in the half of the 19 th century. Several pieces of these dublets were manufactured for astronomical purposes in our workshop in the past. We discuse the mathematical evaluation and the method of manufacture of the glued Steinheil objective with plane exit surface.
Keywords:
Achromatic objective; apochromatic objective; spherochromatic aberration; coma
Available at various institutes of the ASCR
Tmelený objektiv Steinheilova typu
Tento referát se zabývá achromatickými dublety se vstupním členem z flintového skla. Optické řešení těchto objektivů navrhl německý fyzik Carl August Steinheil v polovině 19. století. V nedávné ...
Study on polishing of ZnSe with diamond suspension
Procháska, František; Thoř, Tomáš
2018 - English
Observe the effect of diamond slurries as polishing element on ZnSe, i.e. observe the change of surface of ZnSe as consequence to the series of polishing with the use of mentioned diamond slurries.
Keywords:
ZnSe polishing; Diamond polishing slurry
Available at various institutes of the ASCR
Study on polishing of ZnSe with diamond suspension
Observe the effect of diamond slurries as polishing element on ZnSe, i.e. observe the change of surface of ZnSe as consequence to the series of polishing with the use of mentioned diamond slurries.
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