Constant current versus constant voltage plasma anodization techniques

In this paper a comparison is made between two basic techniques of plasma anodization, i.e. constant current and constant voltage methods. The comparison is based on new mathematical-physical models of both plasma anodization techniques, in which the condition of oxide growth during the process is expressed in terms of fluxes (oxygen ions and electrons) and/or voltages. Detailed analysis of these parameters, their changes during the oxide growth and their comparison enabled the confirmation of some of the experimentally observed effects and to predict others, unnoticed up till now. Based on this analysis it is concluded that the oxide growth during the constant current plasma anodization is not only easier to be monitored and controlled, but also should result in much better anodic oxide electrophysical properties, their better control and repeatability.