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Modern electron beam technologies for fabrication of various materials, powders and metal compositions from a vapour phase

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Paper presents and discusses current achievements of the electron beam application for development of new materials, powders and various material compositions for different use in practice. Streszczenie. Zaprezentowano i przedyskutowano bieżące osiągnięcia wykorzystania wiązki elektronowej przy wytwarzaniu nowych materiałów, proszków i różnych kompozytów materiałowych w przeznaczeniu do wielu praktycznych zastosowań. (Nowoczesna metoda wytwarzania materiałów, proszków i kompozytów metalowych z fazy gazowej przy zastosowaniu wiązki elektronowej) Keywords: electron beam technology, composite material, powder, vapour phase Słowa kluczowe: wiązka elektronowa, kompozyt, proszek, faza gazowa Introduction Electron beam impact on metals leading to their heating, melting and evaporation, as a new technological path in the field of material processing has been intensively developed from the middle of the twentieth century [1,2]. However, up to now most of the companies involved in development and material processing do not get along with electron beam heating. It is related to characteristic features of this method, main of which is possibility of concentration of energy from 103 up to 5·108 W/cm² (i.e. in required range of thermal processing), conduction of the process in vacuum that provides high purity of a processable material and complete automation of this process. Development of the electron beam technology runs along three main paths: - melting and evaporation in vacuum for manufacturing of pure metal ingots, compound alloys, coverings (condensed from a vapour phase), composition materials [3,4,5]; use high power (up to 1 MW and more) electron beam installations at acceleration potential 20 - 30 kV; the concentration of power density is rather insignificant (no more than 105 W / cm²); - welding of metals; equipment of three classes has been developed: low-, mean- and high-voltage, using the acceleration voltage r[...]

Applicability of a multilayer condensed multicomponent material in electrical contacts of LV vacuum interrupters

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Paper presents and discusses investigated results of performance of selected low voltage vacuum interrupters in which the multicomponent multilayer condensed contact material based on Cu-W compositions was used. On the basis of the switching test results followed by respective inspections of the contacts surface and investigations of the microanalysis as well as material morphology the conclusions on possibility of application of such the material composition for LV vacuum interrupters in practice are formulated. Streszczenie. Przedstawiono i omowiono wyniki bada. komor pro.niowych przeznaczonych do stycznika niskiego napi.cia, w ktorych zastosowano nak.adki stykowe Cu-W wykonane metod. kondensacji warstw wielosk.adnikowych. Na podstawie testow ..czeniowych oraz analizy powierzchni i sk.adu chemicznego sformu.owano wnioski dotycz.ce mo.liwo.ci zastosowania takich materia.ow w niskonapi.ciowych komorach gaszeniowych. (Nak.adki stykowe Cu-W wykonane metod. kondensacji warstw wielosk.adnikowych) Keywords: vacuum interrupter, multilayer condensed multicomponent material, electrical contact S.owa kluczowe: komora gaszeniowa, wielosk.adnikowy materia. uzyskany metod. kondensacji, kontakt elektryczny Introduction Fine powder sinters based on copper . tungsten . chromium composition are commonly used as contact materials in quenching chambers of a low voltage vacuum switchgear. However, fine powder metallurgy is a sophisticated as well as money and time consuming technology. Therefore, to replace it by another effective process engineering is both technically and economically justified. The electron beam high-rate evaporation method with following condensation in vacuum seems to be one of such technologies. It has been successfully applied for fabrication of various multilayer composite materials of different thickness up to about 5 mm in Scientific and Production Enterprise ELTECHMASH in Vinnitsa, Ukraine, and used for various arcing conta[...]

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