The effect of acoustic power to an electrochemical system can be considered as a source of activation which influences the mass transport, cleaning and thermal effect at the electrode/electrolyte interface. Enhanced mass transport of species to the electrode’s surface is resulted from ultrasonically induced acoustic streaming and cavitation effects at the electrode / electrolyte interface that maintain the electrode’s activity.
Fig.1. The effect of superimposition of acoustics on the initial potential transients during etching.
Fig 1. indicates that time span of initial potential transient becomes that shorten with acoustics, which manifests the fast breakdown of natural oxide film. Simultaneously, the potential rise rate to the peak potential, equivalent to the anodic film format ion, is greater with acoustics. It suggests that, with the superimposition of acoustic during etching, mass transport of water and chloride ion inside native oxide film can be accelerated.
In this work, the effect of acoustics during the electrochemical anodic etching of aluminum was investigated to increase the pit density and have a uniform tunnel length.
This work was supported by Inha universtiy 2005 reserch grant.