| Project/Area Number |
06650800
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Material processing/treatments
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
AWAKURA Yasuhiro Kyoto University, Graduate School of Engineering, Professor, 工学研究科, 教授 (70109015)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1994: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Chromium plating / Electrodeposition / Chromous Chloride / Chromous Sulfate / Electrolytic Reduction |
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| Research Abstract |
The electrodeposition of chromium and Cr-Zn alloy and Cr-Fe-Ni alloy was examined using a variety of divalent chromium baths. Divalent chromium baths were prepared by electrolytic reduction of aqueous Cr_2(SO_4)_3 solution using a titanium cathode. Lustrous deposits were obtained by electrodeposition using aqueous 0.8 kmol m^<-3> CrSO_4 -0.008 kmol m^<-3> ZnSO_4 -2.0 kmol m^<-3> KCl-0.3 kmol m^<-3> HCOOH (pH 2.4). The deposit contained Zn and Cr-Zn alloy phases. Lustrous Cr-Fe-Ni alloy deposits were obtained at cathode potentials from -1.0 to -1.1 V vs SHE,using aqueous 0.1-0.4 kmol m^<-3> CrSO_4 -0.1 kmol m^<-3> FeSO_4 -0.1 kmol m^<-3> NiSO_4 -1.0 kmol m^<-3> KCl -0.3 kmol m^<-3> HCOOH (pH 2.4). The chromium content in the deposit increased with an increase in the chromium concentration of a plating bath and with a decrease in the cathode potential. For 30 min of deposition, the average current efficiency for Cr-Fe-Ni deposition from divalent chromium baths was 15% to 25%, which was higher than that from conventional trivalent chromium baths.
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