초록
Brass was electrodeposited over the range of the current densities from 2 to 8 A/$dm^2$ in cyanide bath at 20 and 40$^{\circ}C$. The cathode overpotential increased and the cathode efficiency was decreased respectively with decreasing temperature, increasing current density and addition of organic substance. The perferred orientation of the deposits were associated with the cathode overpotential and the nucleation energy of lattice planes. The (111) preferred orientation developed at the low current density and low cathode overpotential (440-520mV). On the other hand, the (111)+(100) preferred orientation developed at higher cathode overpotential (528-680mV). The (111)+(100) preferred orientation developed over the whole range of overpotential in the cyanide solution with organic additive. The copper content of deposit decreased with increasing current density and decreasing temperature. The morphology of the deposits with no additive was the polygonal body type of structure and the structure of the cross section was columnar structure. The morphology of the deposits with additive, on the other hand, was fine crystallite type of structure. And the structure of the cross section of them was the finer granular structure.
