STUDIES ON THE ELECTROCHEMICAL AND CORROSION BEHAVIOUR OF ANTIMONY AND ANTIMONY-TIN ALLOYS IN AQUEOUS MEDIA

Abstract

The first part deals with a general survey of the literature of the electrochemical and corrosion behavior of both Sb and its Sb-Sn alloys in various media. A little work has been done on Sb in alkaline solutions. Polarization measurements have shown that Sb electrode is readily passivated in acidic media. Electrochemical impedance spectroscopy measurements have shown that the oxide film on Sb surface consists of two layers. However, there are few researches on Sb-Sn alloys have been done. The studies have been concerned with the variation of the open circuit potential with time and some polarization measurements only in halide solutions were investigated. But the potentiodynamic and galvanostatic measurements of Sb-Sn alloys have not yet been investigated.

II- The second part is experimental part and deals with the preparation ofSb and its four alloys (10% Sn, 20% Sn, 35% Sn and 50% Sn by atomic weight), a full description of the polarization cell,

electrolytes (KOH, H2 S04, H3P04 , HC104 and Na2 S04 solutions in absence and presence of additives such as halide ions and oxyanions of group VIA, Cro4••, Mo04-- and W04--), and description of the techniques (galvanostatic, potentiodynamic, potentiostatic and electrochemical impedance spectroscopy). The surfaces before and after experiments were examined by X-ray diffraction and SEM.

ill- The third part deals with the results obtained from the

Figures and Tables.