The Effects of Alternating Current on the Properties of Nickel Deposits from an All-Chloride Solution

Abstract

Nickel-chloride plating solutions are highly conducting, have good throwing power, and permit fast plating rates, but the deposits produced with direct current are dark, highly stressed, and have low ductility. Replacement of direct current by variable-pulse-width square-wave alternating current can completely change the character of deposits. Low frequencies, 100 c/s or below, with small amounts of deplating during each cycle, produce lustrous, hard deposits but they remain highly stressed with low ductility. Increased deplating during each cycle, combined with the use of higher frequencies, results in substantial improvements in ductility and reduction in stress. Operation at frequencies of 500 c/s, with relatively large amounts of deplating during each cycle, produces soft, matt, exceptionally ductile deposits, which can be extended 34%, and tensile stress is reduced to values as low as 17,000 lb/in².