The vibrating electropolishing process of aluminium in phosphoric acid solution (1st Report)

Abstract

This study is concerning with the electropolishing process with the vibrating anode in phosphoric acid bath based on the patents-(Jap. Pat. No. 128891, 190520, T-Nakayama)In these experiments the static method and the vibration method have been used symmetrically.(1) As a whole, the electropolished surface produced by the static method has always shown uneven surface, its reflectivity being up to 80%, but the vibration method gave an extremely smooth surface and its reflectivity reached to 90%.(2) In the vibration method, the concentration of phosphoric acid to obtain electropolished surface is higher than that in the static method, but it has been possible to perform electropolishing up to a higher concentration than that in the static.(3) Upon increase of the current density, the surface condition has changed in the order as follows:A (etched surface)-B (insufficient polished surface)-C (electropolished surface)-D (rough surface)-E (burned surface).The similar results can be obtained with each concentration as well as with both the static and the vibration method.(4) With the identical concentration of phosphoric acid, the vibration method produced electropolished surface in a higher current density than the static method, and electropolished surface also can be obtained untill reaching to a higher current density than that of the static.(5) With the same temperature, electropolished surface can be obtained at a higher current density of the vibration method than that of the static, producing electropolished surface untill reaching a higher current density.(6) While the static method produces electropolished surface in short time in comparison with the vibration method, the vibration method produces electropolished surface until reaching to a longer electrolysis time than the static.