Abstract
Voltage-amperage curves for anodizing pure aluminum, 17S, 52S and 61S in sulfuric acid solution with d. c. constant current density can be divided into three types. Electrolytic conditions to get good films of wear resistance are as follows:
1) Initial voltage is high but final voltage low and the rate of film growth also low.
For instance, voltage vs. time curve is parallel to horizontal line (time).
2) Both initial and final voltage are high and the forming voltage increases very fast and the rate of film growth is also high.
For instance, voltage vs. time curve is parallel to vertical line (voltage).
