| 摘要 |
PURPOSE:To form electrodeposited matter in the form of smut and low-karat plating by adding potassium citrate, potassium thiosulfate and a nonionic surfactant to a plating soln. contg. composite cyanogen compounds contg. alkali and gold, silver and copper, respectively and having a low free cyanogen content and a weakly acidic carbonic acid compound as a pH buffer. CONSTITUTION:This Au-Ag-Cu alloy plating soln. has a composition contg. 7-16g/l gold in the form of alkali gold cyanide, 5-11g/l silver in the form of alkali silver cyanide, 10-50g/l copper in the form of alkali copper cyanide, 10-200g/l alkali cyanide, 200-400g/l potassium citrate which accelerates the lowering of plating stress, 0.0001-1g/l potassium thiosulfate which maintains high karat and a nonionic surfactant.
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