Hydrodynamic effects on the macromorphology of electrodeposited zinc and flow visualization: A flat plate electrode in a channel flow cell

Abstract

The macromorphological features of electrodeposited zinc that result from hydrodynamic flow conditions along a flat plate electrode in a channel flow cell have been investigated using acidic chloride solutions (0.1–4.0 M ZnCl 2+HCl) for the current density range 10–100 mA cm −2. All the complex hydrodynamic characteristics of the reattaching flow and the presence of streamwise directed counter-rotating Taylor-Goertler vortices behind the critical region of the stagnation line and separation have been clearly outlined and marked by the macromorphology of three-dimensional relief imprints. The macromorphological features of the deposit depend mainly on the flow rate, electric-field strength, deposition time, ionic zinc content and electrolyte composition. The macromorphological imprints of electrodeposited zinc within a certain current density range could be employed for both the instantaneous and the cumulative (time sequence of photoimprints) electrochemical visualization method.