LOW VOLTAGE HARD ANODIZING PROCESS

摘要

LOW VOLTAGE HARD ANODIZING PROCESS A process for hard anodizing of aluminum and aluminum alloys uses a low DC carrier voltage on which an AC voltage is superimposed. The process enables the electrolyte to have a lower acid concentration than is usual in conventional hard anodizing methods while tolerating higher bath temperatures than are usual. In the process, the DC carrier voltage is kept within the range of 14 to 20 volts for an extended period of time. Preferably, modulation of the DC carrier by the AC voltage does not exceed 100%.