Anodic polarization of Al-Sn alloy in H3PO4 solutions |
| |
Authors: | F H Assaf |
| |
Institution: | (1) South Valley University, Faculty of Science, Chemistry Department, Qena, Egypt, EG |
| |
Abstract: | The anodic polarization behaviour of Al-Sn alloy (5.6% Sn) was studied in aerated 1, 1.5 and 2 M H3PO4 acid solutions using potentiodynamic and potentiostatic techniques. Anodic behaviour of Al and Sn metals was investigated
for comparison. The results show that the alloy exhibits active-passive transition behaviour. The passivation of the examined
alloy is due to the formation of oxide film for both Al and Sn incorporated with their phosphates. In general, at constant
concentration of PO4
3− ion, the passive current density (I
pass) is decreased with increase of pH in the range 2.5–5. Further, the influence of Cl− ions on the passivity of the given alloy was studied. It was found that the aggressive effect of Cl− ions on the passive film is inhibited with increase in phosphate concentration and pH. However, the addition of organic compounds
(2- and 3-picoline and 2-aminopyridine) shows that only 2-aminopyridine inhibited the attack of Cl− ions.
Received: 24 October 1997 / Accepted: 5 February 1998 |
| |
Keywords: | Anodic polarization Aluminium-tin alloy Passivation Chloride Phosphoric acid |
本文献已被 SpringerLink 等数据库收录! |
|