Method for preparing mid-high voltage corrosion foil by using pulse DC superposed current

Abstract

The invention relates to a method for preparing a mid-high voltage corrosion foil by using pulse DC superposed current. The method comprises the following steps of first pretreatment, second pretreatment, first-stage hole generation, intermediate treatment, second-stage hole generation and after-treatment. According to the method, an oxidation film on the surface of an aluminum foil is removed by strongly alkaline solution via the first pretreatment, residual alkaline solution on the surface of the aluminum foil is neutralized by strongly acid solution via the second pretreatment, holes are generated by a pulse DC superposed current method via first-stage hole generation, radius and depth of the holes are further enlarged by direct current via intermediate treatment, and residual aluminum ions on the surface of the aluminum foil are chemically eroded by after-treatment via second-stage hole generation. The whole technical process is simple, adaptability to change of corrosion tank liquid is high and the generated corrosion holes are uniform and smooth so that electrostatic specific volume of the corrosion foil is greatly enhanced, mechanical property is excellent, and the limit that the hole generation process in the conventional corrosion technology cannot be performed in case of power outage is solved.

Description

technical field [0001] The invention relates to the field of preparation of medium and high voltage anode corroded foil, in particular to a method for preparing medium and high voltage corroded foil with pulse direct current superimposed current. technical background [0002] The traditional medium and high voltage anode foil uses a chromic acid corrosion system. The advantage is that due to the strong corrosion ability of chromic acid itself, the current required is small, and it has great advantages in terms of heat generation and static specific volume. However, due to the chromium The acid system is facing more and more serious environmental protection pressure, foreign countries have basically stopped using it, and domestic enterprises are actively eliminating it. [0003] At present, the mainstream corrosion process at home and abroad is generally a mixed acid system of sulfuric acid and hydrochloric acid. The basic process includes pretreatment→first-level hole openin...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the defects and deficiencies of the prior art, and propose a method for preparing medium and high voltage anode foil corroded foils with pulsed DC superimposed current, which can solve the problem of uneven holes and excessive heat generation in the process of primary hole formation. Problems such as high weight loss rate, low mechanical properties and low electrostatic specific capacity caused by erosion during the secondary expansion process

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