Texture and morphology of pulse plated zinc electrodeposits

Zinc coatings were deposited under pulse-current plating conditions from an acidic sulphate bath on low-carbon steel cathodes. The effect of the (peak) deposition current density, duty cycle and pulse frequency on the microstructural texture and morphology of the deposits was studied by X-ray diffractometry and scanning electron microscopy. The zinc films consisted of crystallites having an average size controlled by deposition current density, and oriented mostly with basal (00.2) and high index (10.3), (10.4), (10.5) pyramidal planes parallel to the surface. Pulse plating resulted in coatings which were microstructurally different to those prepared under similar conditions by direct current deposition. Texture and grain size modification is illustrated. The effect of pulse current is explained in terms of enhanced nucleation and inhibited growth. C 2006 Springer Science + Business Media, Inc.