National University of Science and Technology MISIS, Moscow, Russia

T. S. Sarkisov, Department of Metal Forming, Engineer of the Research Project, e-mail: tiksar@ya.ru
S. S. Sarkisov, Lead Expert of the Research Project, Department of Metal Forming, Candidate of Technical Sciences, e-mail: sarkfoil@yandex.ru

JSC ELECOND, Sarapul, Russia

S. V. Rybin, Deputy Chief Engineer for Science and Engineering, e-mail: rybinsv@elcudm.ru
E. L. Lyapunova, Head of the Laboratory, Department of Aluminum Capacitors

The authors in their recent papers studied influence of thermal deformation modes on a set of physical and mechanical properties of foils from aluminum grade А99 for low-voltage and high-voltage anodes and cathodes of electrolytic capacitors. This study is devoted to influence of microalloying of high purity aluminum with scandium and zirconium on forming physical (electric capacity and leakage current) and mechanical properties (ultimate tensile strength) of capacitor foils. The subject under study is 14 laboratory samples of aluminum foil, including 2 samples of basic aluminum grade А99 with and without intermediate annealing; 6 samples with microalloying with scandium, wt.%: Al + 0.05 Sc; Al + 0.1 Sc; Al 99 + 0.3 Sc (with and without intermediate annealing); 6 samples with microalloying with zirconium, wt.%: Al + 0.05 Zr; Al+ 0.1 Zr; Al + 0.3 Zr (with and without intermediate annealing). The samples were studied after their static rate setting in terms of high-voltage and low-voltage application modes. Low-voltage foil showed increased specific capacity, when scandium content was 0.05 wt.%; when a subsequent increase in a parameter was from 0.1 to 0.3 wt.%, specific capacity decreased, but strength properties of foils improved. Leakage currents increased within a total range of alloying with scandium from 0.05 to 0.3 wt.% for such type of foils. Microalloying of low-voltage foils with scandium improves strength properties, but does not provide a positive effect on electrical parameters. When adding zirconium into pure aluminum in a range of 0.05 to 0.3 wt.% for low-voltage and high-voltage foils, electrical parameters show no improvement, but strength properties increase. When introducing intermediate annealing, capacity increases for all the samples tested for high voltage modes, and decreases for low voltage modes. Microalloying of high purity aluminum with Sc and Zr is efficient, when the content is increased to 0.05 wt.% for foils of cathode applications, when there is no need for forming an oxide layer of a dielectric material.

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