亜鉛-ニッケル合金めっき皮膜の組成に及ぼす電極電位の影響

抄録

The deposition of zinc-nickel alloy on gold plated substrates from sulfate electroplating baths was investigated by potentiostatic electrolysis with respect to the effect of electrode potential on the composition of alloy deposits. The electrodeposits were analyzed by atomic absorption spectrophotometry, X-ray photoelectron spectroscopy (XPS), X-ray diffraction and, for their metal element content, by anodic chronoamperometry. We found that since both zinc and nickel dissolved as divalent ions in sulfate solution and nickel is always included as metal element in alloy deposits by XPS studies, the analytical values obtained for the zinc and nickel elements by both anodic chronoamperometry and atomic absorption spectrophotometry permitted the evaluation of the content of metallic zinc and metallic nickel and the summation of zinc monoxide and zinc dihydroxide in alloy deposits as well.
The partial quantity of electricity for deposition of metallic zinc sharply increased at potentials near -0.99V (Ag/AgCl sat. KCl). Both zinc monoxide and zinc dihydroxide were always included in alloy deposits obtained at potentials more noble than -0.99V and were never found at potentials of around -0.99 to -1.00V. At potentials less noble than -1.00V, however they were included in alloy deposits again when alloy deposition current and especially hydrogen evolution current increased.