Influence of coumarin on zinc electrodeposition

Continuous current was used to study the effect of coumarin on zinc deposits from chloride bath. Scanning electron microscopy (SEM) was used to analyze the morphology of the deposits. The preferred orientations of the deposits were also investigated. At J = 4 A/dm2, the (112) texture of zinc electrodeposited without additive changes to a (110) texture in presence of coumarin. The corrosion behaviour was investigated in aerated 3.5% NaCl solution as well as under anodic polarization curves, polarization resistance (Rp) measurements and weight-loss studies. The corrosion resistance of zinc deposits was improved by the use of coumarin as additive.