Characterization of innovative rotary swaged Cu-Al clad composite wire conductors

Abstract

Cu/Al composites are perspective for applications in a wide range of industrial and commercial branches, from transportation to elecatrotechnics. This study focuses on Cu/Al clad composite wires with 5 mm diameter featuring unique sequencing produced via the technology of rotary swaging at the processing temperatures of 20 degrees C and 250 degrees C. During the swaging process, we continuously acquired samples for investigations and used our own KOMAFU S600 system for dynamic detection of swaging forces. The composite wires subjected to electrical resistivity measurement were further analysed via electron microscopy, neutron diffraction, and mechanical testing. The results showed that both the total imposed strain (swaging degree) and swaging temperature influenced the investigated parameters non-negligibly. The samples subjected to high reduction ratios (swaging degree > 3) at the temperature of 250 degrees C exhibited formation of intermetallics at the interfaces, which deteriorated the electric conductivity. However, the conductivity was also affected by structural phenomena, such as work hardening, texture development, dislocations density, and recrystallization. All the final 5 mm samples exhibited sufficient bonding of both the components and recrystallized ultra-fine grained structures providing them with the ultimate tensile strength of >200 MPa.