抄録
Etch-pits of various shapes were obtained when aluminum was anodically dissolved in chloride solutions. Studies were therefore conducted on predicting by computer simulation the shape of the etch-pit formed under various conditions. Aluminum of 99.99% purity was electrolytically etched in 0.85M HCl and it was found that: a) etch-pit diameters were smaller at 90°C than at 25°C, at 2, 000 Am-2 than at 500Am-2, and 5, 000Cm-2 than at 30, 000Cm-2; b) pit depth increased with increasing the electricity of etching; c) pits were square in shape under all conditions. A theoretical equation was derived from anodic dissolution theory for simulation purposes, and simulation for the etching morphology was carried out on the HITAC M-280H computer of the University of Tokyo. Constants in the literature were used for the digital simulation, and results were output in the form of contour line plots and cross-sectional profiles. The surface profile after a given anodization time was plotted by three-dimensional contour lines and in cross-section. Comparison with observations a), b), and c) of actual etching showed good agreement.
