STRENGTHENING AND SUSCEPTIBILITY TO ANNEALING OF COPPER AND ALUMINUM

1 KNYCH Tadeusz
Co-authors:
1 SMYRAK Beata 1 ZASADZIŃSKA Małgorzata 1 JURKIEWICZ Bartosz 1 GNIEŁCZYK Marek 1 KORDASZEWKI Szymon 1 GRZEBINOGA Justyna
Institution:
1 AGH University of Science and Technology, Faculty of Non-Ferrous Metals, Krakow, Poland, UE email: malgozas@agh.edu.pl
Conference:
26th International Conference on Metallurgy and Materials, Hotel Voronez I, Brno, Czech Republic, EU, May 24th - 26th 2017
Proceedings:
Proceedings 26th International Conference on Metallurgy and Materials
Pages:
306-312
ISBN:
978-80-87294-79-6
ISSN:
2694-9296
Published:
9th January 2018
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
38 views / 18 downloads
Abstract

The abnormal prices of copper and aluminum over the last decade have led to increasing substitution of copper with aluminum. This is mainly possible due to the favorable relation of the strength properties of aluminum to its density with respect to copper. An aluminum conductor with the same length and the same resistance has twice the weight of a copper conductor. The main technological problem of substituting copper with aluminum lies in the technology of drawing small diameter aluminum wires and their annealing on-line. In recent years, this problem has been effectively solved by introducing dedicated aluminum alloy grades and a new generation of rod breakdown machines and multiwire machines that allow drawing aluminum using emulsions with simultaneous annealing of online wires in a way similar to annealing copper wires. Due to the high stacking fault energy of aluminum in relation to that of copper, the aluminum alloy is characterized by a recovered structure, which translates into low susceptibility of the aluminum wires to annealing. This problem is not observed with copper wires. The article includes the results of studies of the process of strengthening Cu-ETP copper wire rods and EN AW-1350 aluminum wire rods, and the annealing characteristics (softening curve) observed during the hour-long annealing process. The structures of wires after drawing and after annealing. The analysis of the studies shows that the temperature of recrystallization of aluminum wires is about 200 ° C higher than that of copper wires of the same deformation degree. There was a significantly different recrystallization kinetics of the studied wires (different angle of slope of the UTS = f (T) characteristic), which translates into the need for other current settings in the annealing line in production lines.

Keywords: copper wires, aluminum wires, EN AW-1350, Cu-ETP, annealing, recrystallization, strain hardening, softening curve
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