| 摘要 |
PROBLEM TO BE SOLVED: To provide aluminum foil from which the cathode foil for electrolytic capacitor having a large capacitance and a high tensile strength is obtained. SOLUTION: The aluminum foil has aluminum purity of >=99.8 wt.%. On the surface of the foil, crystallized particles having particle sizes of 0.5-4.5μm exist at a rate of 500-2,000 particles/mm2. The surface crystallized particles have a mean particle diameter of 30-70μm and the maximum particle size of the particles does not exceed 150μm. This aluminum foil can be manufactured in such a way that an ingot containing Fe at a rate of 0.02-0.08 wt.% and aluminum at a rate of 99.8 wt.% is first prepared. Then the ingot is subjected to homogenizing treatment for a period of time of 0.5-3 hours under a temperature condition of 500-550 deg.C. Thereafter, the ingot is hot-rolled and successively cold-rolled so that the rolling reduction may become >=95%. Finally, finish annealing is performed on the rolled ingot under a temperature condition of 250-350 deg.C.
|
