Use of Microelectrodes in the Study of Stress Corrosion in Aged Al–7·2 wt-% Mg and Al–4·4 wt-% Cu Alloys

Abstract

The preparation of reference Ag/AgCl microelectrodes and their application to the measurement of localised corrosion potentials is described. Such measurements have been made in the grain boundary regions of aged Al–7·2 wt-% Mg and Al–4·4 wt-% Cu alloys. The results have been correlated with bulk corrosion measurements on the various constituents of the microstructures and related to the initiation of stress corrosion cracks in these alloys.