Phase Structure and Morphology of Zinc-Iron Alloy Electrodeposits

Zinc-iron alloy electrodeposits are providing higher corrosion resistance to steel components and also having better mechanical properties when compared to zinc deposits. This is due to the unique phase structure of the alloy formed. This study elucidates the phase structure of the electrodeposited alloy, based on the deposition kinetics and morphological characteristics. Deposition of iron was hindered by charge-transfer process, at low current densities. But zinc deposition was prevailed through diffusion control, only at high current densities. The probability of substitution of iron in hcp lattice along c-axis is more, than a-axis. This is because the linear density along c-axis is lower than a-axis. Intermetallic compounds of variable compositions were identified. Compounds such as FeZn16, FeZn13, Fe5Zn78 have dominantly "eta" phase structure and FeZn6, Fe5Zn22, Fe2Zn7, Fe5Zn29, Fe3Zn13 have "Gamma" phase structure.