Morphology and Texture of Zinc Deposits Formed at the Edge of a Rotating Washer Electrode

P. R. SERE; L. N. BENGOA; W. A. EGLI; M. S. CONCONI

JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE

SPRINGER

Año: 2016 vol. 25 p. 2936 - 2942

1059-9495

In this paper, a rotating washer electrode was used to simulate the industrial conditions of strip edgesduring electrogalvanizing. Using this experimental setup, morphology and texture of the zinc deposits anddendrites formed at the edge of the electrode were studied. Dendrite precursors in the corner of the washeredge were well characterized and their nucleation and growth were also studied. The results indicated thatthe rotation speed has little effect on texture while, in contrast, current density modifies dendrites texture. Itwas found that dendrites are formed by platelets which are stacked on one another, which grow up in aseries of steps oriented in the direction of growth of the dendrites stem yielding highly oriented structure.The presence of sodium ions in the electrolyte changes the morphology and shape of dendrites leading torounded, cabbage-shaped crystals, while thiourea changes the morphology of both the deposit in the flatportion of the washer and the dendrites through adsorption on the zinc surface.