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- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 42413 (07)
- University: Sharif University of Technology
- Department: Materials Science and Engineering
- Advisor(s): Ghorbani, Mohammad
- Abstract:
- Electrodeposion of Zn-Ni Alloy Nanometer Multilayer has been studied. The investigations show that Multilayer coatings have more corrosion resistance than a Monolayer. The electrodeposition of the multilayer coatings was performed with the single bath technique. The sulfate-borate bath has been used for electrodeposition of the Multilayer coatings. The switching cathode density current has been used for the multilayer coatings in cathode current densities of 20, 30, 40, and 50 mA.cm-2. The number of layers with constant overall thickness of 2 µm was 20, 40, 80, and 100. The composition of layers varied between 5-11% wt Ni with the values of cathode current densities. The Response Surface Methodology was utilized for optimization of the effective parameters on corrosion current densities. The polarization analysis has been carried out on coatings for the corrosion resistance study. The studies show corrosion resistance increase when the number of layers increases. The Response Surface Methodology data based on polarization results shows that a coating with 50-20 mA.cm-2 of cathode current density and 100 layers has the highest corrosion resistance. The surface coating and cross section study was done with SEM. EDAX and AAS analysis has been used for chemical concentration. The morphology and roughness were studied with AFM. The hardness of coatings has been measured with Microhardness and had been showed hardness increase when the number of layers increases. The Mechanism of electrodepostion was studied with electrochemical methods of Chronoamperometry and Cyclic voltammetry and the studies show electrodeposition was Three-dimensional and instantaneous
- Keywords:
- Electrodeposition ; Multi-Layer Coating ; Zinc-Nickel Alloy ; Single Bath Method ; Sulfate-Borate Bath
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