Abstract
We studied the mechanism behind the double-zincate process, used for pretreating aluminum alloy, through SEM observation, electrode potential tracing, and weight changes determined during each zincate process. Zinc particles grew during the first zincate process, with a thin, uniform Zn layer forming during the second zincate process. We found that the difference in zinc particle nucleation between the first and second processes is related to surface morphology and in thickness nonuniformities in the preexisting oxide film air-formed on the alloy.
