Surface-Roughness Evolution During the Cementation of Silver Ions on Solid Copper in Aqueous Sulfuric Acid Solution
✍ Scribed by Grzegorz D. Sulka; Marian Jaskuła
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- German
- Weight
- 970 KB
- Volume
- 89
- Category
- Article
- ISSN
- 0018-019X
No coin nor oath required. For personal study only.
✦ Synopsis
The evolution of the surface roughness during cementation of Ag + conducted either in O 2 -free or O 2saturated aqueous H 2 SO 4 /CuSO 4 was investigated at two different initial concentrations of Ag + . The kinetics data of the process determined previously in the rotating cylinder were linked directly with scanning-electron-microscope (SEM) images and surface-height-distribution diagrams calculated for various cementation times. It was found that, at the beginning of the process, the surface roughness decreases due to formation of a flat Ag layer on the top of the surface, independent of the presence or absence of O 2 in the system. With increasing reaction time, an increase in the surface roughness was observed. The rate enhancement of the process is mainly responsible for the increase of the surface roughness in the O 2 -saturated solutions, especially at the higher initial Ag + concentration (100 mg/dm 3 ). The rate enhancement observed at a latter stage of the process, connected with the increase of the effective surface area of the cathodic sites, was separated from the rate enhancement induced by the competitive chemical process occurring in O 2 -free solution. The difference in the mechanisms of the processes conducted under aerobic and anaerobic conditions was reflected in the surface-heigth distributions calculated from the SEM images.