Electrochemical characteristics of FeAl3 intermetallic compounds phase in a simulated pit solution

Abstract

The standard Gibbs free energy of FeAl3 has obtained to be - 58.8 kJ/mol. The electrochemical characteristics has been investigated in terms of occurrence of selective or spontaneous dissolution of components of intermetallic compound phase FeAl3 in a 0.1 kmol/m3 NaCl + 0.5 kmol/m3 AlCl3 solution. It is discussed that the existence of approximate value of 10 ppm ferrous ions detected at constant potentials of - 0.8 V and - 1.2 V vs. Ag/AgCl may attribute to the sequential reactions in the electrochemical processes: selective dissolution of aluminum component in FeAl3 phase and then dissolution of enriched iron portion which is separated from the surface of the phase by agitation of the hydrogen gas evolution.