クエン酸を含有する硫酸塩浴からのZn電析の臨界電流密度 [in Japanese] Critical Current Density for Zinc Deposition from Sulfate Baths Containing Sodium Citrate [in Japanese]
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The critical current density at which massive Zn deposition began was measured in Zn and Zn-Ni alloy plating baths containing sodium citrate.<br>Results were as follows:<br>(1) The Zn deposition potential from citrate-containing baths was 0.1V less positive than from citrate-free baths, iudicating that citrate behaves as a complexing agent with Zn ion.<br>(2) Ni partial polarization curves also shifted to a less positive region with the addition of citrate in Ni and Zn-Ni alloy plating baths.<br>(3) The addition of sodium citrate and a decrease in pH in baths increased the Zn critical current density.<br>(4) pH in the cathode layer attained the value for Zn hydroxide formation at the critical current density in both citrate-containing and citrate-free baths.<br>Since the pH for Zn hydroxide formation is higher in citrate-containing than citrate-free baths, the critical current density at which adsorbed Zn hydroxide suppresses the hydrogen evolution rate to initiate massive Zn depositions is increased by the addition of citrate to baths.
- Jitsumu Hyomen Gijutsu
Jitsumu Hyomen Gijutsu 48(6), 647-652, 1997-06-01
The Surface Finishing Society of Japan