Study of changes in microstructure and metal interface Cu/Al during bimetallic construction wire straining
Irina Volokitina, Bayan Sapargaliyeva, Aktolkyn Agabekova, Andrey Volokitin, Samal Syrlybekkyzy, Alexandr Kolesnikov, G. A. Ulyeva, Almas Yerzhanov, Pavel Kozlov
Abstract
This article investigates the effect of a new processing technology on the change in microstructure and mechanical properties of bimetallic aluminum-copper wire. This technology makes it possible to produce a new generation of wire for use in the construction of new overhead lines and reconstruction of old ones. The study was conducted using a transmission electron microscope, EBSD analysis, tensile tests, and determination of microhardness and electrical conductivity. The results of the study show that an ultrafine-grained copper-aluminum composite with a gradient structure is formed during straining by ECAP-drawing. Annealing after straining at 200 °C increases the strength of the interfacial connection between Cu and Al and improves the strength characteristics of the bimetallic aluminum-copper wire. The use of such aluminum-copper wires for overhead transmission lines allows to reduce the wire cross-section and, accordingly, wind loads, as well as to increase the strength properties without an additional increase in the total weight of the wire.