S. Akbarzadeh, S.r. Allahkaram, S. Mahdavi,
Volume 15, Issue 2 (6-2018)
Abstract
Tin-Zinc alloy coatings have many applications because of their unique properties such as corrosion resistance, solderability and flexibility. In this study, the effect of current density, temperature and pH on chemical composition, cathodic current efficiency, morphology and structures of the coatings was investigated. The results illustrated that, at low current densities (<0.5 mA/cm2), the coatings were relatively pure tin, but Zn content increased with enhancing the current density. At higher currents a relatively pure Zn film was obtained. Temperature and pH also affected chemical composition of the alloy films. Zn content of the coatings was decreased by increasing the temperature, while its variation with pH had ascending-descending trend. Morphological investigation of the coatings revealed that increasing Zn content of deposits led to porous, rough and fine grained films.
Daniela Grigorova, Gyunver Hodjaoglu, Feyzim Hodzhaoglu,
Volume 21, Issue 0 (3-2024)
Abstract
Producing high-purity iron powders with controlled particle morphology is essential for advanced powder metallurgy, additive manufacturing, and functional materials. However, achieving precise morphological control in environmentally benign, additive-free electrolytes remains challenging. This study systematically investigates the galvanostatic electrodeposition of iron powder from sulfate-based electrolytes containing 10.0 and 50.0 g·L⁻¹ Fe²⁺, focusing on the interplay between current density, pH evolution, deposition efficiency, and particle structure. A clear transition from compact, adherent deposits at low current densities to dendritic, easily detachable powders at higher values was observed. SEM analysis revealed well-defined dendritic aggregates at 7 A·dm⁻² (30–80 μm), whereas highly fragmented, porous agglomerates formed at 10 A·dm⁻², accompanied by fine-scale fragmentation driven by intense hydrogen evolution. XRD confirmed pure α-Fe for current densities up to 7 A·dm⁻², while partial oxidation to Fe₃O₄ occurred at 10 A·dm⁻²; EDX mapping further supported this surface oxidation. The deposited mass increased linearly with current density for both Fe²⁺ concentrations, with regression models yielding R² values above 0.96. Current efficiency decreased at high current densities due to enhanced parasitic reactions. Overall, the results demonstrate that galvanostatic electrodeposition in additive-free sulfate media enables controlled synthesis of iron powders, with tunable morphology and phase purity governed primarily by current density and electrolyte composition.
