, including phosphate-chromate method, acid chromate method, and alkaline chromate method, is the concernful treatment method for chemical conversion [9-12].
They also concluded that, for higher frequencies, a correlation does not exist between the resistive component of the impedance and the features of the chromate treatment
These observations may reflect real differences between the two types of chromate or alternatively may be related to exposure time as soluble chromate treatment
was only for 2 h while the barium chromate treatment
was for 24 h (32).
In addition to zinc phosphates, pretreatments for aluminum and aluminum alloys include chrome phosphate (green chromate), chrome chromate (gold chromate), other chromate treatments
, and anodizing.
Similar to chromate treatments
, (16,17) rare earth elements do form durable aluminum alloy surface conversions but do not appear to passivate anodic corrosion reactions.