• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2007년도 추계학술대회 논문집
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• pp.26-26
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• 2007

To attest zinc electrodeposition mechanism, electric circuit models for zinc electro reaction on Pt electrode are analyzed from the a.c. impedance data. Electrochemical reactions of zinc deposition are composed of the three electrochemical reactions on the cathode layer and of the induced electrode layers.

• 한국표면공학회지
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• 제27권1호
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• pp.45-53
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• 1994

A kinetic study on the electrodeposition of zinc-iron alloys onto a steel in chloride solutions has been car-ried out using a rotating disc geometry. The results show that the deposition rate was increased with electropotential, disc rotation speed and temperature, and consequently the rate was partly controlled by elec-trochemical reaction and partly by mass transport. The iron content of deposit was more increased with cell voltage than with disc rotating speed and temperature. During electrodeposition process, the addition of metal-lic zinc powder retards oxidation rate of $Fe^{2+}$.

• 한국표면공학회지
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• 제20권1호
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• pp.4-14
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• 1987

The nickel-zinc alloy depositions have been studied in nickel chloride added chloride baths, to find out the effects of ultrasonic irradiation for the electrodeposition processes. The compositions of deposited alloys, the current efficiencies and the metallographic appearances in various conditions of Electrodeposition were investigated, in the range of ultrasonic irradiation of 50,500 and 1,000 Kc/s respectively. The results obtained are as follows; 1. Generally the nickel deposition process is more preferably activated than that of zinc by the ultrasonic irradiation. 2. The radios of nickel to zinc in the deposit are higher according to increase of nickel ion concentration and bath temperatures in irradiated baths. 3. The current efficiencies are also higher in the irradiated baths, so that the depolarization effect is noticeable. 4. The brightness and leveling effect of the deposits are appreciably better in the irradiated baths than in non-irradiated in 0.3M and 0.6M of nickel chloride and zinc chloride solutions and the current density of 3A/$dm^2$. 5. The mechanism of alloy deposition has been tentatively suggested in the case of ultrasonic irradiation.

• 한국전기전자재료학회논문지
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• 제30권11호
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• pp.705-709
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• 2017

Effective surface area and morphology of a sensitive thin film are important factors for its applications in sensor systems for the analysis of physical properties. In this study, we investigated the morphologies, electrochemical properties, and applicability of zinc oxide multilayer thin films fabricated by electrodeposition and annealing. The microstructure and electrochemical properties of the zinc oxide films were dependent on temperature and applied voltage. The best characteristics were obtained at an applied voltage of -1.4 V and a temperature of $50^{\circ}C$. The morphologies also changed upon annealing. The results suggest that the zinc oxide films fabricated by electrodeposition and annealing can be applied as various sensor materials.

• 한국표면공학회지
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• 제21권4호
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• pp.168-175
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• 1988

The nickel0zinc allot depositions have been studjen in ammonium chloridw added chloride baths to fine out the effects of ultrasonic irradiation for the electrodeposition processes. The compositions of deposited alloys, the current efficiencies, corrosion resistance and brightness in various conditions of electrodeposition were investigated, in the range of ultrasonic irradiation of 50,500 and 1,000kc/s respectively. The results obtained are as follows; 1. the ratio of nikel to zinc in the deposit increased according 시 the ammonium chloride concentration in irradiated baths. 2. The current efficiencies became also higer in the irradiated bath. 3. Ammonium ions in solution seem to retard formation of zinc hydroxide. 4. The corrsion resistance and brightness of the deposits are dependent upon nickel content of deposits which ranges 10-18%(wt)nickel in the irradiated baths and 11-15%(wt)in ninirradisted baths. 5. The corrosion resistance and brightnes of the deposited are appreciably better in the irradiated baths than in non-irradiated bath with the mole ratio of 3.4(NH+4/Ni+++Zn++).

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2003년도 춘계학술발표회 초록집
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• pp.48-48
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• 2003

• 한국표면공학회지
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• 제22권3호
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• pp.118-127
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• 1989

The rate of electrodeposition Zinc-nickel alloy on to electrolytic ione in sulface solution both under an inter and air atmospherss has studied by use of a rotating disc geometry. The kinetics shows 1st order reaction, and the rate constants are proportional to the square root of rpm, however, they are less than the valuse suggested by Levich. The rate constants of zinc deposition approach the total mass transfer rate constants with increasing potential and deviate with increasing rotaing speed, but those of nickel deposition are constant. Below $40^{\circ}C$ the activation engrgies of zinc deposition and nikel deposition were 4.4Kcal/mol and 6.3Kcal/mol respectively. There results show that overall reaction rate of zinc-nickel plaeting is controlled by mixed reaction and zinc deposotion is more affected by mass transfer reaction than nickel. The current density for the zinc-nickel plating was less in an air atmosphere than in a nitrogen atmosphere. The cathode efficiency increased with decreasing cathode rotating speeds, potentials, and increasing temperatures. Zzinc-nickel platings are more improved in microhardnss than zinc platings.

• 한국표면공학회지
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• 제37권5호
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• pp.263-272
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• 2004

High strength steels such as transformation induced plastic steel, dual phase and solid solution Hardening have been developed and continuously improved due to the intensified needs in the automotive industry. But silicon and manganese in transformation induced plastic steels were known to exhibit harmful effects on galvannealing reaction by oxide film formed during heat treatment. Therefore, in this work, the applicability of Zn-Ni electrodeposition instead of hot dip galvannealed coating to transformation induced plastic steels was evaluated and optimum electroplating condition was investigated. Based on these investigations optimized electroplating conditions were proposed and Zn-Ni electrogalvanized steel sheet was produced by EGL (electrogalvanized line). Its perfomance properties for automotive steel was evaluated.

• 한국재료학회지
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• 제12권2호
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• pp.146-152
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• 2002

Effect of polyaniline and additives on surface appearance of Zn electrodeposition was investigated by SEM and XRD analyzing. We carried out the experiment from sulfate Zinc bath containing sulfonated polyaniline, gelatin and thiourea by EG(Electrogalvanizing) simulator. Addition of polyaniline and gelatin in bath, crystal size and shape of hexagonal plane of Zn crystal reduced. Mixing of thiourea, however, brittle deposits were observed because of the difference between vertical growth and parallel growth. (1011) peak appeared with polyaniline and gelatin in XRD analysis. In case of mixing of polyaniline, gelatin and thiourea, (1011) peak appeared and intensity of Zn basal plane decreased. These results suggested that overpotential increased with addition of polyaniline and additives In bath.

• 한국표면공학회지
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• 제29권4호
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• pp.219-228
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• 1996

Neutral Zinc Electroplating(NZE) utilizing the electrolyte of pH 6 to 8 has advantages in waste treatment and the protection of equipment. NZE is beneficially used in chromating treatment, but the limiting current density and the current efficiency are low. Therefore this study is investigated to analyse the characteristics of NZE and to obtain high current density and current efficiency. The deposition potential of zinc in the NZE bath is about 110mV, which is lower than acidic bath. The current density possibily increases up to 60A/d$\m^2$ in lower complexing agent content and pH 6. More than 90% of cathodic current efficiency was obtained in NZE bath. The NZE morphology shows smaller grains than acidic bath. The addition of 4$m\ell$/1 second brightener gives finer morphology. As pH becomes higher, (002) plan decreases and (100), (101) and (110) planes increase in the no additives solution.