Intergranular corrosion propagation rate of 2024 alloy investigated via the “one-​dimensional artificial pit” technique

This study is based on the description of the intergranular corrosion (IG) of 2024 aluminium alloy considering the dissolving paths consist of precipitated free zones at the grain boundaries where intermetallic precipitation is occurring. Assuming IG paths to be pore-shaped electrodes, it was demonstrated that “one-dimensional artificial pit” pure aluminium electrodes can be used to approach the IG corrosion growth rate. The same trend, i.e. the decrease of the dissolution rate as function of the depth of the defect (initial pore depth of the machined “one-dimensional artificial pit” or maximum depth of IG penetration) was observed for the two experiments.