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IJCT Vol.14 [2007] >
IJCT Vol.14(3) [May 2007] >
| Title: | Electrodeposition and compositional behaviour of Zn-Ni alloy |
| Authors: | Thangaraj, V
Hegde, A Chitharanjan |
| Keywords: | Zn-Ni alloy
Chloride bath |
| Issue Date: | May-2007 |
| Publisher: | CSIR |
| IPC Code: | C25D3/56 |
| Abstract: | This paper discusses the optimization of an electroplating bath for smooth and uniform deposition of zinc-nickel alloy on mild steel. Electroplating has been carried out in a chloride bath using glycine and gelatin as additives. The effect of bath conditions and operating parameters on chemical composition, micro-hardness and appearance of the deposit have been studied and discussed. The experimental results reveal that a bright Zn-Ni alloy having about 13.6 %Ni is showing good performance against corrosion. The corrosion resistance of the deposit is found to be characteristic of its %Ni content, and is improved drastically after chrome passivation. The bath follows anomalous codeposition with preferential deposition of Zn over the entire current density range used for the study. The increase of %Ni in the deposit with current density is due to the depletion of more readily depositable Zn²⁺ ions at the cathode. No transition current density, at which the codeposition behaviour changed from the anomalous to normal type, was observed during the study. The increase of %Ni in the deposit at high current density (c.d.) is attributed to high ratio of Ni²⁺/Zn²⁺ in the bath. The effect of temperature on the plating process showed that codeposition of metals on the cathode is diffusion controlled. |
| Page(s): | 246-252 |
| ISSN: | 0971–457X |
| Source: | IJCT Vol.14(3) [May 2007]
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