Likhatskyi R. PRODUCTION OF HEAT-RESISTANT ALLOYS OF THE Cu-V AND Cu-Cr-Zr-V SYSTEMS IN THE CONDITIONS OF ELECTRON-BEAM CASTING TECHNOLOGY

The dissertation examines the production of cast low-alloy heat-resistant copper alloys for electrotechnical purposes under the conditions of electron-beam casting technology. The regularities of the influence of alloying on the properties of copper alloys were substantiated, and a number of experimental studies were conducted, on the basis of which the optimal content of alloying elements was determined. It is shown that the content of vanadium in the alloy up to 0.3 wt.% makes it possible to obtain a uniform distribution of finely dispersed spherical inclusions of vanadium (up to 2 μm). It is shown that the secondary remelting of Cu-V alloys by induction melting does not lead to a decrease in the properties of the alloy. Modeling proved the determining role of convective flows in the movement of small vanadium inclusions in the copper melt (provided that there is a small amount of vanadium) and determined the specifics of the influence of casting parameters on the distribution of alloying elements after crystallization. The possibility of significantly reducing the amount of chromium and zirconium in the charge when doping chromium-zirconium bronzes with vanadium has been experimentally proven. Such alloys have high electrical conductivity and mechanical properties at elevated temperatures, which, with a simpler technology for obtaining alloys, compared with the most widely used methods of powder metallurgy, shows the expediency of their smelting by methods of electron-beam casting technology.