Galvanostatic Deposition of Iron Powder from Sulfate Electrolytes: Experimental Analysis and Empirical Modeling

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 ۱۰.۰ and ۵۰.۰ 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 ۷ A·dm⁻² (۳۰–۸۰ μm), whereas highly fragmented, porous agglomerates formed at ۱۰ A·dm⁻², accompanied by fine-scale fragmentation driven by intense hydrogen evolution. XRD confirmed pure α-Fe for current densities up to ۷ A·dm⁻², while partial oxidation to Fe₃O₄ occurred at ۱۰ 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 ۰.۹۶. 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.

کلیدواژه ها:

iron powder ، galvanostatic electrolysis ، sulphate electrolyte ، current efficiency ، SEM morphology