Hydrodynamic effects in the electrodeposition of Au-Cu-Cd alloys: An experimental and numerical study

Previous studies in this group proved that the single most critical factor affecting control of the Au-Cu-Cd electrodeposition process from free-cyanide baths is fluid dynamics. In this paper we report on an experimental and numerical study of compositional effects of fluid flow, including the design, construction and testing of a laboratory-scale flow-cell for alloy electrodeposition. Full elliptic three-dimensional computation of fluid flow was carried out with the FLUENT code. A flow-cell implementing the computed flow conditions was built and Au-Cu-Cd electrodeposition experiments were carried out. Compositional maps of deposits grown in the flow-cell were measured by energy dispersive spectroscopy and compared with computed fluid flow distributions. It was deduced that low and high flow through the cell give rise to local compositional inhomogeneities and macroscopic compositional trends, respectively.