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Vol.46, No.11, 725 ~ 730, 2008
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| Title |
| The Effect of Complexing Agents on the Deposit Characteristics in the Electroless Nickel-Tungsten-Phosphorus Plating |
| 조진기 Jin Ki Cho , 박상욱 Sang Wook Park , 강성군 Seung Goon Kang , 손성호 Seong Ho Son |
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| Abstract |
| Deposition characteristics of electroless plated Ni-W-P films were investigated for various complexing agents. Used complexing agents are sodium citrate, sodium gluconate and sodium malonate. In this study, the existing mixed potential theory could explain the overall mechanism of Ni-W-P electroless plating for all complexing agents. The deposition rate could be also expected by the theory. The deposited Ni- W-P films were evaluated in term of surface hardness and corrosion resistance. Microhardness of the deposit increased about 1,000 Hv after heat treatment for one hour at 400℃, because it was above the crystallization temperature of Ni3P. The deposited Ni-W-P films can exhibit excellent corrosion resistance in using sodium malonate as a complexing agent, the other hand the using sodium gluconate was the worst corrosion resistance. The worst corrosion resistance was due to a large number of nano-sized pin-holes or small pores. The plating current at the mixed potential increases when the using sodium malonate as a complexing agent, it was explained by the cross section. |
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| Key Words |
| electroless deposit, complexing agent, mixed potential, surface hardness, corrosion resistance |
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