| Summary: | 碩士 === 國立中央大學 === 機械工程研究所 === 96 === Micro-anode guided electroplating (MAGE) of nickel from the bath of ionic liquid system such as choline chloride, including choline chloride/urea and choline chloride/ethylene glycol, has been investigated. Experimental parameters such as bath temperature, electrical bias, gap between two electrodes, mole ratio of ethylene glycol to choline chloride in the bath, addition of boric acid in the bath were concerned to explore their influence on the morphology of the Ni-deposit. Electron scanning microscopy (SEM) was used to examine the
morphology of the deposits. The current in the depositing process was monitored. Finite element analysis was employed to comprehend the electroplating mechanism of MAGE in the ionic liquid system by virtue of
electric field strength, electron transfer process and the rate of mass transfer.
With increasing bath temperature, the viscosity of the electrolyte decreased. The decrease of viscosity results in diffusion enhancement of the electro-active species thus facilitating their mass transport. The conductivity of the system was found to increase with increasing the ratio of ethylene glycol to choline chloride in the bath. The strength of electric field will reduce if the initial gap between the electrodes is extended or less electrical bias was employed. The bath involved boric acid tends to maintain a constant pH value and the possible formation of nickel hydroxide could be prevented.
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