The effect of texture and surface morphology on the corrosion resistance of zinc electrodeposits

摘要

Texture plays a major role in the corrosion resistance of zinc electrodeposits. This isbecause the grain dissolution rate depends on its orientation. In the presentinvestigation, zinc coatings were electrodeposited from an acidic sulfate bath oncarbon steel substrate. The effects of substrate surface preparation and additives ofoxalate and Sn~(+2) ions on texture and surface morphology of deposits were evaluated.The corrosion behavior of zinc electrodeposited coatings was investigated in 5 wt.%NaCl solution. It was observed that the corrosion resistance of zinc electrodeposits isrelated to the crystallographic planes exposed to aggressive solution, and not onlythe planes of texture components. The findings highlight the role of surfacemorphology of the coatings in exchange current density of water reduction and itssubsequent effect on corrosion resistance.