Morphology and texture of pulse plated zinc-cobalt alloy

Pulse electrodeposition was used to produce zinc-cobalt (Zn-Co) alloy deposits from an alkaline non-cyanide electrolyte with and without additives. The influence of additives' concentration and pulse parameters, such as ON-time (T-ON), OFF-time (T-OFF), and pulse peak current density (I-p) on the surface morphology, grain size, composition and crystal orientation were investigated using scanning electron microscope (SEM), atomic forced microscope (AFM), energy dispersive X-ray (EDX), X-ray fluorescence (XRF), X-ray diffraction (XRD), respectively. At constant T-OFF and I-p, cobalt content in the deposits decreases with TON and cluster size increases. Increase in T-OFF at constant T-ON and I-p, decreases the cluster growth with increase in cobalt content. The same trend was observed with increasing Ip (without additives) at constant TON and TOFF. The presence of additives at 7 Adm(-2) drastically decreases the cobalt content in the deposits from 2.5 to 0.7 wt.%. Co and the preferred crystallographic orientation was [10.1] at 69.1% as confirmed by XRD. (C) 2009 Elsevier B.V. All rights reserved.