National University of Science and Technology MISiS, Moscow, Russia:

S. S. Sarkisov, Senior Lecturer at the Department of Physics, e-mail: sarkfoil@yandex.ru

This paper describes a research study into the effect of final annealing (temperature, heating rate, isothermal time; if there is a low-temperature stage) on the performance of aluminium foil for high-voltage capacitor anodes, i. e. on such properties as specific capacity, ultimate strength, relative elongation. The foil made of high purity aluminium (99.99% Al) was produced by cold rolling of an 8 mm hot-rolled strip, which was reduced to 0.100 mm with no interannealing applied and with the total cold deformation of 98.7%. The author demonstrates how the annealing temperature and heating rate can influence the specific capacity, ultimate strength, relative elongation, and the average grain size. A relationship was found between the properties of anode foil and the way its structure and texture formed at different annealing regimes. An increased specific capacity of the foil associated with the increase of the annealing temperature to 450 ^oC indicates that there is a direct relationship between the former and the average grain size and the maximum orientation of the cubic texture. Within this temperature range, the coarser the grains are, the higher the specific capacity is. At the annealing temperatures of 500 ^oC and higher, a weaker cubic orientation {200} and stronger bounces {220} and {311} can be observed, while the specific capacity and mechanical properties deteriorate.

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