塩酸溶液中の三角波パルス電流エッチングで生ずるアルミニウムのピット形態と表面皮膜
1999 年 50 巻 2 号 p. 212-217
詳細
1999 年 50 巻 2 号 p. 212-217
The effect of the current waveform on etch morphology and surface film of aluminum produced in 3.6% HCl solution at 323K was studied using scanning electron microscopy (SEM) and Auger spectroscopy (AES). Current forms used for etching were asymmetrical triangular anodic pulses having a maximum current density of 0.5A/cm2 at tm within an on time of 10-2s, and the off time between pulses was varied from 0 to 0.1s. The change of the etched surface depended on tm, and off time was found due to the amount of etch products composed of an anodic film of Al2O3 shown by AES analysis and a small quantity of aluminum hydroxide observed by SEM. The etched morphology was classified into three stages by current sweep rate. Above 200A/cm2s (tm<2.5×10-3s), it remained partly unattached area. Fine pits were produced at 125∼200A/cm2s (tm=2.5∼4×10-3s) where an anodic film several nm thick developed. Large pits having a diameter of ≥30μm yielded to the thicker anodic film at less than 100A/cm2s (tm>5×10-3s). The anodic film thickness increased with increasing tm and off time.
