PURPOSE:To reduce the loss of Co due to the scooping of a plating soln. as well as to obtain a high rate of codeposition of Co in spite of a low Co content of the soln. by specifying the amts. of zincate and Co forming a chelate compd. in the plating soln. and the pH of the soln. CONSTITUTION:The subject electroplating soln. contains 5-20g/l (expressed in terms of Zn) zincate, 0.02-1g/l Co ions (0.002-0.1 pt.wt. Co per 1 pt.wt. Zn) forming a chelate compd. and an effective amt. of a brightener and is kept at pH=13. Gluconate, glucoheptonate or citrate may be used as the chelating agent of the chelate compd.
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