تاثير دانستيه جريان و آماده سازي سطح فولاد بر مورفولوژي و بافت رسوب الكتريكي روي

Effect of Current Density and Surface Preparation of Steel on Morphology and Texture of Zinc Electrodeposits

On electropolished steel, at low current densities, morphology and texture of zinc electrodeposited were investigated Zinc coating is consisted of hexagonal crystallite laid on each other to produce packets. These packets have different size, and are stacked in different orientations to construct a homogeneous coating on steel substrate. This coating does not have texture, i.e. it has random texture. With increase of current density, the morphology changes completely as each grain attains a special orientation. In this case, coating has a strong basal (0002) along with low angle planes (1013 and 1014). Coating obtained on mechanically polished surfaces is consisted of individual packets of zinc crystals, which are near each other with different orientations. These coatings have a higher density of basal plane (0002) in comparison to electropolished surfaces. The morphology and texture variations with cathodic polarization and surface preparation of steel are due to their effect on nucleation and growth.