The effect of production parameters for electron-beam deposition of two-layer metal − ceramic coatings in one production cycle on the structure and phase composition of the outer ceramic layer based on zirconium oxide stabilized with yttrium oxide is studied. It is shown that it is possible to obtain metal − ceramic coatings with the required functional properties in one production cycle.Two-layer protective metal − ceramic coatings are used extensively in engine building in order to protect gas turbine blades [1][2][3]. It is well known [1] that in order to deposit the inner metal layer there is use of MCrAlY (where M is nickel, cobalt, iron), and for the outer ceramic layer there is use of zirconium dioxide ZrO 2 stabilized with yttrium oxide Y 2 O 3 (Yttrium Stabilized Zirconium Oxide, YSZ). The life of blades with this two-layer coating is governed to a considerable extent by deposition parameters. In spite of the extensive results of research devoted to this question [1][2][3][4][5][6][7] there are no published clear recommendations for deposition of these coatings.Normally two-stage technology is used in order to form two-layer metal − ceramic coating on turbine blades. The inner metal layer is applied to an article by means of vacuum plasma spray (VPS); air plasma spray (APS) or electron-beam physical vapor deposition (EB-PVD). A method used in the production cycle for two-layer coating deposition is shot-blasting treatment of the surface of the metal layer followed by annealing in a vacuum furnace with the aim of "healing" structural defects in the deposited layer [3]. Sometimes in order to obtain the required roughness before deposition of the outer ceramic layer the surface of the inner metal layer is subjected to hydraulic-abrasive treatment by a water emulsion of clay [4] and only then is the outer layer applied by one of the methods mentioned.Until recently in the economically developed European countries and the USA the preferred method for applying metal − ceramic protective coatings has remained plasma deposition. In some of the leading engine building firms of the world, in particular "Pratt and Whitney," there is use of a combined method for preparing two-layer coatings. The inner MCrAlY coating is applied by plasma deposition and the outer ceramic layer is applied by electronbeam deposition. Use of different equipment complicates the production process and makes it more expensive. A fundamental solution of the problem is deposition of a two-layer metal − ceramic coating in one type of equipment in one production cycle. We note that the effect of using two-layer metal − ceramic coatings depends to a considerable degree on the perfection of the production processes. It is considered [1][2][3]8] that the electron-beam method for depositing the outer ceramic layer has certain advantages compared with plasma deposition, i.e. increased cyclic endurance in thermal cycling for the ceramic layer obtained.Scientific-Production Enterprise "GEKONT," Vinnitsa, Ukraine.

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The paper presents modern developments in the field of powdered composite materials of pseudoalloy type based on Cu (Ag) and refractory metals W (Mo, Cr), used as electric contact materials and welding electrodes. Main requirements made of materials of arcing contacts and resistance welding electrodes are briefly described. Main data from world manufacturers on compositions and regulated characteristics of this material type are given, and main process schematics of their manufacturing are listed. Certain technological difficulties of producing nanodispersed composites are pointed out that slow down their production on an industrial scale. It is noted that application of mechanical alloying method during high-energy milling of powders allows producing copper, dispersion-strengthened by refractory oxides and carbides (Al2O3, TiO2, Cr2O3, SiO2, etc.) with recrystallization temperature close to that of copper melting and higher level of electric conductivity, strength and oxidation resistance, compared to chromium and chromium-zirconium bronzes. 41 Ref., 5 Tables , 4 Figures.

The paper presents the method of electron beam vacuum evaporation and condensation for the most promising technologies of manufacturing modern composite materials, used in welding and switching equipment. This method currently is one of the components of the technological process of producing thin (up to 5 mm) films for radio engineering, microelectronics, computer engineering, etc., as well as thick (more than 5 mm) films-condensates widely applied as effective protective and wear-resistant coatings. Described are the results of scientific and production activity on introduction into industry of technologies of deposition of thick films based on copper and refractory metals (molybdenum, tungsten, chromium) with additives of REM and other metals (yttrium, zirconium) on the surface of electric contacts and electrodes. Proceeding from the results of trials performed in more than 54 enterprises of Ukraine, Russia, Georgia, Rumania, Poland and PRC it was established that the developed materials are not inferior to silver-containing powder compositions in terms of serviceability, while being approximately 3 times less expensive than the latter. 57 Ref., 1 Table, 4 Figures.

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