• Korean Journal of Materials Research
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• v.27 no.8
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• pp.409-415
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• 2017

For enhanced cavitation erosion resistance of vessel propellers, an electroless Ni-P plating method was introduced to form a coating layer with high hardness on the surface of Cu alloy (CAC703C) used as vessel propeller material. An electroless Ni-P plating reaction generated by Fe atoms in the Cu alloy occurred, forming a uniform amorphous layer with P content of ~10 wt%. The amorphous layer transformed to (Ni3P+Ni) two phase structure after heat treatment. Cavitation erosion tests following the ASTM G-32 standard were carried out to relate the microstructural changes by heat treatment and the cavitation erosion resistance in distilled water and 3.5 wt% NaCl solutions. It was possible to obtain excellent cavitation erosion resistance through careful microstructural control of the coating layer, demonstrating that this electroless Ni-P plating process is a viable coating process for the enhancement of the cavitation erosion resistance of vessel propellers.

• Resources Recycling
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• v.21 no.2
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• pp.41-46
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• 2012

An investigation on the recovery of nickel from spent electroless plating solutions has been performed using the electrowinning method. For this aim, nickel in spent electroless plating solutions was separated as nickel hydroxide through the addition of caustic soda. Nickel hydroxide was completely dissolved with sulfuric acid and an electrolysis was performed for electrowinning of nickel from nickel solutions. As a result, it was found that more than 99% of nickel in spent electroless plating solutions could be precipitated as nickel hydroxide above pH 10 with the addition of caustic soda. As far as the current efficiency in electrowinning of nickel was concerned, it was decreased with increase in the current density.

• Corrosion Science and Technology
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• v.21 no.2
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• pp.89-99
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• 2022

A versatile method for performing non-cyanide electroless gold plating using thiomalic acid (TMA) as a complexing agent and 2-aminoethanethiol (AET) as a reducing agent was investigated. It was found that TMA was an excellent complexing agent for gold. It can be used in electroless gold plating baths at a neutral pH with a high solution stability, makes it a potential candidate to replace conventional toxic cyanide complex. It was found that one gold atomic ion could bind to two TMA molecules to form the [2TMA-Au⁺] complex in a solution. AET can be used as a reducing agent in electroless gold plating solutions. The highest current density was obtained at electrode rotation rate of 250 to 500 rpm based on anodic and cathodic polarization curves with the mixed potential theory. Increasing AET concentration, pH, and temperature significantly increased the anodic polarization current density and shifted the plating potential toward a more negative value. The optimal gold ion concentration to obtain the highest current density was 0.01 M. The cathodic current was higher at a lower pH and a higher temperature. The current density was inversely proportional to TMA concentration.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.829-831
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• 2003

In the present study, the electroless plating method was applied instead of the sputtering as a formation method of metallic bus electrodes. No additional blackening step is needed in this method since this process provides a metallic seed layer with black color by a single step. The parameters which affects color and morphology of the metallic seed layer in the electroless plating solution were investigated

• Journal of the Korean institute of surface engineering
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• v.36 no.5
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• pp.393-397
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• 2003

The effects of the composition and additives on the blackening and deposition rate of electroless Ni-Zn plating have been examined. Hydrazine resulted in lower sheet resistance of the deposit than sodium hypophosphite. Zinc concentration more than 15 wt% and small amount of ammonium sulfate in the deposits were needed in obtaining Ni-Zn deposit with a black color. An optimum condition was obtained for the black Ni-Zn deposit at an appreciable deposition rate.

• Fashion & Textile Research Journal
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• v.10 no.3
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• pp.385-388
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• 2008

Four kinds of PET fabrics were coated with Copper and Nickel by electroless chemical plating, and the electromagnetic wave shielding effectiveness for those samples have been examined. The shielding effectiveness showed between 90 dB and 70 dB, and it related to the fabric structure, such as cover factor and cloth density. The dense fabric structure showed the better shielding effect.

• Journal of the Korean institute of surface engineering
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• v.40 no.3
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• pp.131-137
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• 2007

The typical MCFC (molten carbonate fuel cell) anode is made of Ni-10%Cr alloy. The work of this paper is focused concerning long life of anode because Ni-10% Cr anode is suffering from sintering and creep behavior during cell operation. Therefore, Ni-coated Alumina powder($20{\mu}m$) was developed by electroless nickel plating. Optimum condition of electroless nickel coation on $20{\mu}m$ alumina is as follows: pH 11.7, temperature $65{\sim}80^{\circ}C$, powder amount $100cm^2/l$. The deposition rate for Ni-electroless plating was as a function of temperature and activation energy was evaluated by Arrhenius Equation thereby activation energy calculated slope of experimental data as 117.6 kJ/mol, frequency factor(A) was $6.28{\times}10^{18}hr^{-1}$, respectively.

• Journal of the Korean institute of surface engineering
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• v.33 no.4
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• pp.273-280
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• 2000

Silver was deposited on glass by electroless plating and electroplating. Surface properties were investigated using the AFM. Crystal structure of deposit layers was confirmed by TEM and XRD. Electroplating is performed by DC plating and pulse plating, respectively. This study resulted in followings, first, deposit of electroless plating showed fine grain and was similar to the amorphous structure. Second, electrodeposit on the electroless layer was revealed following results ; (1) more uniform layer and finer grains were obtained with increasing frequency (2) more isotropic structure was obtained with increasing frequency (3) finer grains at 25% duty cycle was obtained (4) grain size and roughness of the silver deposit was decreased with increasing frequency.

• Journal of Power System Engineering
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• v.10 no.3
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• pp.58-66
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• 2006

The effect of bath composition, plating condition and plating rate on the magnetic properties of electroless Ni-Cu-P deposits were investigated. With increasing $CuSO_4$ concentration in the bath, plating rate increased, while the Br value of deposits decreased Sharply. Plating rate increased up to 34% with the addition of 200ppm of NaF and 0.8ppm of Thiourea to the bath. Plating reaction had been ceased by the increase of pH above 11.3, bath temperature higher than $90^{\circ}C$ and under $70^{\circ}C$. The Br value of deposit was uniform with various concentration of complexing agent (Sodium citrate, Ethylenediamine) in the bath. The Br value of deposit was almost equal to that found by the addition of stabilizer(Thiourea) and accelerator(NaF). The Br value of deposit was uniform in plating time(120 min) and heat treatment temperature(below $200^{\circ}C$), and were confirmed to have adequate bath stability for practical use.

• Journal of the Korean institute of surface engineering
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• v.43 no.2
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• pp.47-50
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• 2010

This work discusses a two-step electroless plating method for preparing a Pt thin film on p-type InGaAs substrate, which is defined as Pt I and Pt II. A thin Pt catalytic layer formed in Pt I bath on the substrate at $65^{\circ}C$. In the following Pt II bath, thick Pt films then easily grew on the sensitized layer on InGaAs previously formed in the Pt I bath. The growth of Pt film is strongly influenced by the plating temperature and pH value. To study the plating time effect, the plating of Pt II bath is 5 to 40 min at $80^{\circ}C$ after using Pt I bath at 50~$65^{\circ}C$ for 5min of pH 8~13. Pt film for ohmic contact to p-type InGaAs was successfully prepared by using the two-step Pt electroless plating.