Research Article
Porous Layer Characterization of Anodized and Black-Anodized Aluminium by Electrochemical Studies
Table 1
Black anodizing process parameters.
| Sl. no. | Process | Concentrations | Process parameters |
| 1 | Black dyeing | Jet black—11 g L−1 | pH = 5 ± 0.5 | (Commercial organic black dye procured from Khatau Valabhdas, Gujarat, India) | 75 ± 5°C 15 min |
| 2 | Inorganic colouring | Step 1: | 25 ± 5°C | Cobalt acetate, Co(C2H3O2)2—200 g L−1 | 15 min | Step 2: | 25 ± 5°C | Ammonium sulphide, (NH4)2S—25 mL L−1 | 15 min |
| 3 | Electrolytic colouring | Sulphuric acid, H2SO4—10 mL L−1 | pH = 1.1 ± 0.3 | Stannous chloride, SnCl2—20 g L−1 | 25 ± 5°C | Phenol sulphonic acid—10 mL L−1 | Voltage ~20 V, AC | | 15 min |
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*Each step was followed by demineralized water rinsing.
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