Automated alternating polarity direct current pulse electrolytic processing of metals

摘要

Disclosed is a method and apparatus for electrolytic processing of a metal surface which, in a preferred embodiment, is anodization of an aluminum or aluminum alloy surface. An apparatus and method is provided which automatically senses the process voltage applied to the surface to be anodized and adjusts the duration of anodizing current pulses accordingly. Direct current anodizing pulses are interrupted by non-anodizing pulses which may be either zero current or reverse current pulses. The ratio of anodizing to non-anodizing pulse power is varied during anodizing such that the anodizing to non-anodizing time power ratio is reduced. In a preferred embodiment, a microprocessor follows the process voltage necessary to maintain a constant current flow to the metal surface and reduces the anodizing to non-anodizing time power ratio in a predetermined manner.