PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 5

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Preparation and noise analysis of polymer graphite cathode
Knápek A., Horáček M., Chlumská J., Kuparowitz T., Sobola D., Šikula J.
Metrology and Measurement Systems
|
2018
|
Vol. 25, nr 3
451--458
EN
The paper deals with the preparation and measurement of an experimental polymer graphite cathode that seems to be a promising and cheap source of electrons utilizing cold field-emission in high- and ultra-high vacuum. Polymer graphite seems to be a proper material as it contains a large amount of hybridized carbon with a low degree of surface oxidation and silicon monoxide (SiO). Within the frame of this work, a special experimental method of tip preparation has been designed and tuned. This method is based on ion milling inside a dual-beam electron microscope enabling to obtain ultra-sharp tips of a diameter smaller than 100 nm with a predefined opening angle. The charge transport within experimental samples is evaluated based on results provided by the noise spectroscopy of the total emission current in the time and frequency domains.
2
Content available Gating systems for sizeable castings from Al alloys cast into ceramic moulds
Stachovec I., Horáček M., Zemčík L., Kolda V., Horenský J.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 2
65-68
EN
In contrast to casting to conventional non-reusable 'sand' moulds, for which calculating technique for an optimum design of the gating system is comparatively well-developed, a trial-and-error method is applied mostly for casting to ceramic shell moulds made by the investment casting technology. A technologist selects from gating systems of several types (that are standardized by the foundry mostly) on the basis of experience. However, this approach is not sustainable with ever growing demands on quality of castings and also the economy of their fabrication as well as with new types of complex sizeable castings introduced to the production gradually (by new customers from the aircraft industry above all) any more. The simulation software may be used as a possible tool for making the process of optimising gating systems more effective.
3
Content available Applying RP-FDM technology to produce prototype castings using the investment casting method
Macků M., Horáček M.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 3
75-82
EN
The research focused on the production of prototype castings, which is mapped out starting from the drawing documentation up to the production of the casting itself. The FDM method was applied for the production of the 3D pattern. Its main objective was to find out what dimensional changes happened during individual production stages, starting from the 3D pattern printing through a silicon mould production, wax patterns casting, making shells, melting out wax from shells and drying, up to the production of the final casting itself. Five measurements of determined dimensions were made during the production, which were processed and evaluated mathematically. A determination of shrinkage and a proposal of measures to maintain the dimensional stability of the final casting so as to meet requirements specified by a customer were the results.
4
Content available remote Accuracy of investment castings
Horáček M.
Archiwum Odlewnictwa
|
2005
|
R. 5, nr 15
121--137
EN
In the paper the analysis of wax pattern and casting dimensions changes during each stages of investment casting technology process has been presented. Results of wax patterns and castings of test plate free and restrained contractions dimensions changes research carried out in Department of Foundry Engineering at Brno University of Technology have been presented as well. Moreover obtained results were compared with results of casing “industrial” casting dimension changes research.
PL
W artykule przedstawiono analizę zmian wymiarowych modelu woskowego i odlewu w poszczególnych etapach procesu odlewnia metodą traconego wosku. Przedstawiono także wyniki badań zmian wymiarowych odlewów płyty testowej ze skurczem swobodnym i hamowanym przeprowadzonych Katedrze Odlewnictwa Politechniki w Brnie, które skonfrontowano z badaniami przeprowadzonymi na przemysłowym odlewie obudowy.
5
Ověření vlastností vybraných modelových směsí a posouzení jejich vhodnosti pro použití v podmínkách slévárny přesného lití
Pšeja Z., Horáček M.
Zeszyty Naukowe. Mechanika / Politechnika Opolska
|
2001
|
Vol. 279, z. 72
141-144
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.