R. Ambat et al., THE INFLUENCE OF AGING AT 180-DEGREES-C ON THE CORROSION BEHAVIOR OF A TERNARY AL-LI-ZR ALLOY, Corrosion science, 37(8), 1995, pp. 1253-1265
The influence of aging at 180 degrees C on the corrosion behaviour of
an Al-1.5%Li-0.1%Zr alloy has been studied using weight loss, open cir
cuit potential (OCP) measurements and potentiodynamic polarization mea
surements in 3.5% NaCl solution. Corrosion rates obtained from weight
loss and I-corr values decreased for samples aged up to 6 h at 180 deg
rees C whereas I-corr increased for samples aged for longer times. Val
ues of OCP and pitting potential initially shifted in the noble direct
ion and then towards more active values. This change in OCP was observ
ed on samples that had been aged for 20 h while in the case of pitting
potential an aging time of only 6 h was required. The overall change
in passive current density was small, although at longer aging times (
> 40h) it showed an increase. As the amount of lithium depletion incre
ased, OCP and pitting potential shifted in the active direction while
passive current density showed an increase. The results have been inte
rpreted in terms of the microstructure.