• Journal of the Korean Electrochemical Society
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• v.5 no.1
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• pp.17-20
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• 2002

Various compositions of CoFeNi alloys have been electrodeposited in chloride bath and in sulfate bath, and evaluated for electrodeposition characteristics and magnetic properties. For electrodeposited CoFeNi thin film alloys, the increase of Fe content in the deposits from sulfate bath was considerably faster than those from chloride bath. The current efficiencies in sulfate bath showed observable decrease from $75\%\;to\;50\%$ while those in chloride bath showed no significant decrease. From the low coercivity of 3 Oe in the minimum and the higher squarenesses of the alloys from sulfate bath than those from chloride bath, the alloy at Co, Fe, and Ni contents of $80wt.\%,\;10wt.\%,\;and\;10wt.\%$ can be considered to be the best CoFeNi alloy in this research for the soft magnetic material.

• Journal of Surface Science and Engineering
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• v.33 no.5
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• pp.339-348
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• 2000

The study was conducted on the effect of bath composition on the surface appearance, the hardness and the crystal orientation of zinc electrodeposits from the chloride bath. (1) The hardness of the zinc electrodeposits from the chloride bath was increased by suppressing mass transfer of zinc through adding the organic additives and the chlorine ion in the electrolyte. (2) The surface whiteness of zinc deposits was decreased due to the change of the preferred orientation from (002) , (103) to (101) , (100) through increasing the organic additives and chlorine ion in the electrolyte. (3) The addition of Cu, Sn, Ni or Co in the chloride bath elevated the hardness of the zinc deposits but darkened the surface whiteness. (4) The optimum condition of the organic additives and the chlorine ion for increasing the hardness of zinc deposits and preventing dark surface ranges 0.3 m1/1 to 0.4 m1/1 and 6.5 mol/1 to 6.8mol/l respectively.

• Journal of Surface Science and Engineering
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• v.43 no.2
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• pp.51-56
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• 2010

The zinc electroplating with respect to the chloride concentration was investigated by X-ray diffraction(XRD), scanning electron microscope (SEM), and cathodic polarization measurement. The cathodic overpotential during electroplating was first decreased and then increased with increase of chloride concentration in electrolyte. The decreased cathodic overpotential leads to preferred orientation of (002) plane, high current efficiency and satisfactory zinc deposits. The increased cathodic overpotential causes random orientation, low current efficiency and edge burning. The cathodic overpotential was affected by chloride concentration in electrolyte, not by the kind of chloride, such as NaCl and KCl. An optimized chloride concentration was 3 M for zinc electroplating. Also, it is considered that NaCl can be a alternation for KCl as a main salt of zinc electroplating bath.

• Journal of Surface Science and Engineering
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• v.27 no.6
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• pp.319-326
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• 1994

The effects of electrolysis conditions on the composition and preferred orientation of Ni-Fe alloy were studied using the sulfate-chloride baths paddle agitated. Cathode current efficiency is higher in the deposits from bath 2 than that of deposits from bath 1. The Fe content of alloy deposits from bath 2 is nearly constant(19∼21wt.%) in the wide range of current density, while it decreases noticeably with current density in the deposits from bath 1. The variation of Fe content at the edge of specimen is lower in deposits from bath 2 than those from bath 1. The alloy deposits show (111) & (200) preferred orientation for the deposits from bath 1 and bath 2 respectively.

• Journal of Surface Science and Engineering
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• v.21 no.4
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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++).

• Journal of Surface Science and Engineering
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• v.53 no.1
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• pp.1-8
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• 2020

Sulfamate-chloride baths were fabricated to study the properties of the electrodeposited Ni and NiCo thin films. The dependences of current efficiency, deposit composition of Ni and Co, residual stress, surface morphology and microstructure of electrodeposited Ni and NiCo thin films on CoCl₂ concentration in sulfamate-chloride baths were investigated. The current efficiency was measured to be more than about 90%, independent of the changes of CoCl₂ concentration in the baths. Residual stress of Ni and NiCo thin films was increased from about 45 to about 250 MPa with varying CoCl₂ concentration from 0 to 0.210 M CoCl₂ in the baths and then reached to a plateau, about 250 MPa above 0.420 M CoCl₂ concentration. Nodular surface morphologies were observed at most CoCl₂ concentrations in the baths except 0.210 M. NiCo thin film electrodeposited from the bath with 0.210 M CoCl₂ concentration showed an acicular surface morphology. Pure Ni thin film consists of FCC(111), FCC(200), FCC(220), and FCC(311) peaks without any preferred orientation. On the other hand NiCo thin films make up of HCP(100), FCC(111), HCP(101), FCC(200), FCC(220) or HCP(110), FCC(311) or HCP(112) and FCC(222) peaks. It was revealed from the analysis of XRD result that FCC(111) peak at the NiCo thin film electrodeposited from the bath with 0.084 M CoCl₂ concentration can be regarded as the preferred orientation. However the peak of the preferred orientation was changed to FCC(220) or HCP(110) above 0.084 M CoCl₂ concentration in the baths. Then the intensity of FCC(220) or HCP(110) peak was gradually decreased with increasing CoCl₂ concentration further. The crystalline size of pure Ni thin film was observed to be about 53 ㎛ and those of NiCo thin films were in the range of 35~45 ㎛.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2000.05a
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• pp.24-24
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• 2000

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.3 s.31
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• pp.242-251
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• 1989

The purpose of this study was to investigate the changes in easy-care and strength properties of the wet fixation processed viscose rayon fabrics. Rayon fabrics were treated with mixed resins of melamine formaldehyde (MF) and DMDHEU by one bath and two bath wet fixation processes. The MF/DMDHEU mixed resin concentrations were 50/100, 50/150, 100/100, 100/150 and 150/100(g/1). Magnasium chloride was used as a catalyst. Treated fabrics were evaluated by nitrogen content, DP rating, wrinkle recovery angle, breaking strength, tearing strength and abrasion resistance. The properties were compared to the fabrics treated by conventional Pad-Dry-Cure (PDC) method. Wet fixation processed fabrics showed DP ratings of higher than 3 and higher than 275 degrees of wrinkle recovery angles in all the mixed resin concentrations. Wet fixation processed fabrics showed increase in breaking strength and tearing strength but decrease in abrasion resistance. However, the decrease in abrasion resistance was much less than the conventional PDC treated fabrics. The one bath wet fixation processed fabrics showed better physical properties than the two bath processed fabrics in general. The optimum treatment condition was the mixed resin concentration of MF/DMDHEU, 100/100 g/l in one bath wet fixation process.

• Journal of Surface Science and Engineering
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• v.20 no.3
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• pp.118-126
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• 1987

The Zn-Al composite electroplating was studied by using chloride zinc bath containing metal hydroxides $(Zn(OH)_2,\;Al(OH)_3))$ and aluminium powder. The size of Al powder codeposited in the beaker bath with Al powder of-400 mesh was under 10${\mu}m$. The Zn-Al composite was electro-deposited at 40$^{\circ}C$ in the ranges of current density of 5-50 A/$dm^2$ in the flowing electrolyte. The content of aluminium particles codeposited increased slightly with increasing flow rate of electrolyte from 0.5 m/sec to 1.0 m/sec, and decreased with increasing current density from 5 A/$dm^2$ to 50 A/$dm^2$. The content of aluminium particles codeposited by using the electrolyte containing zinc hydroxide(0.1M) was 2~4 wt%. The Al powder was codeposited mainly near the surface layer of the electrodeposits. The dissolution rate of aluminium particles in the electrolyte containing 0.1M $Zn(OH)_2$ and Boric acid was 0.41 g/l. day in comparison with 1.5 g/l. day dissolution rate in pure chloride bath.

• Journal of Surface Science and Engineering
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• v.29 no.4
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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.