Influence of process parameters on the cathode current efficiency of Zn/SiO_2 electrodeposition

摘要

Cathode current efficiency (CCE) of Zn/SiO_2 composite electrodeposition bath was investigated. Influence of current density, particle loading, bath agitation, deposition time and bath additive were given particular attention. It was revealed that CCE and particle content in the deposit were inversely proportional to one another with increase in particle loading up to 80g/l, beyond which both decreased. Influence of time on CCE for different particle loadings shows that CCE was significantly higher for baths with lower amount of particles than those with higher amount of particles. However, CCE shows an increasing trend with bath agitation for both 13g/l and 26g/l particle loading with that of 26g/l being higher for all amplitudes investigated. Also, addition of NaNO_3 additive into the bath was found to improve the CCE of the bath. Influence of current density was investigated for a bath with 104g/l of SiO_2. The results show a sharp decrease in CCE from current density of 15A/dm~2 and were constant for higher current densities up to 30A/dm~2. Morphological changes accompanied changes in CCE.