Recrystallization of Silver Electrodeposits at Room Temperature

Abstract

The recrystallization behavior of silver electrodeposits obtained from a low-cyanide silver plating solution containing selenocyanate as an additive was studied using XRD and SIM measurements.
For bright deposits obtained at 120A/dm², the as plated deposits consisted of randomly oriented small crystallites with very weak XRD patterns, deposits hardness was ca. Hv 100. Several hours after plating, the crystallites of the deposits kept at room temperature grew into large crystallites that were predominantly parallel to the substrates. The peak height of the (200) plane of the deposits increased dramatically. Accordingly, the hardness of the deposits decreased drastically to ca. Hv 50.
In contrast, matt silver deposits obtained at 40A/dm² produced no recrystallization phenomena at room temperature after plating. The difference between the deposits coincides with the amount of codeposited selenium in the deposits. Bright deposits containg lower levels of selenium than matt deposits. recrystallized easily compared with matt deposits.