| dc.description.abstract | The main propose of this research is to investigate the high purity aluminum foil(99.95%) hole-etching behaviors under different current wave forms which are triangle, sine, and square waves. Furthermore, the Galvanodynamic Voltammetry Polarization (GVP) and electroresist-to-time graphs are utilized for electrochemical analyses.
By observing the hole etching profiles of aluminum foils with Field Emission Gun Scanning Electron Microscopy (FE-SEM), it shows that the etching surface profiles change with different current forms. The results shows; 1.Applying triangle wave, the etching profiles are cubic and continuous down the foil surfaces. 2. Applying sine wave, the etching profiles reveal irregular and etching directions are down from the surface of foils. 3. For square wave, there are etching holes with bar shapes along one specific direction.
Moreover, because of the characteristics of different currents, the structures of oxide films are discrepant. It infers that: 1. For triangle wave, the rise speed of current is slow that forms oxide films of fine structure. 2. For sine wave, it takes little time to reach max current that produces loose-structure oxide films. 3. For square wave, the current suddenly comes to plus and minus max that electrochemically etches aluminum foils without forming oxide films on the surfaces. | en_US |