Iron-based substrates with polyethylene glycol coating were prepared as possible materials for biodegradable orthopedic implants. Biodegradable materials that provide mechanical support of the diseased tissue at the time of implanting and then disappear gradually during the healing process are sometimes favored instead of permanent implants. The implant degradation rate should match the time of the tissue regrowth. In this work, the degradation behavior of iron-based foams was studied electrochemically during immersion tests in Hanks’ solution. The corrosion rate of the polyethylene glycol-coated samples increased and the corrosion potential shifted to more negative values. This indicates an enhanced degradation rate as compared to the uncoated material, fulfilling the goal of being able to tune the degradation rate. It is the interfacial interaction between the hydrophilic polymer layer and the iron surface that is responsible for the enhanced oxidation rate of iron.

The basic ideas of the earlier developed model of electrolytical plating of metallic powder particles have been applied for calculation of the amount of Ni coating layer on Fe powder particles. The shapes of the calculated curves are in good agreement with the experimental results. The reasons for low current efficiency on the powder particles are explained. Besides the important parameters such as the size of the powder particles and density of the electrolyte - powder suspension, mainly the influence of rotation speed of the suspension in cathodic compartment upon the amount of metal deposited on powder has been analysed. The influence of this parameter upon the electrode process becomes remarkable with increasing rotation speed which has been explained by combination of two effects: the contact resistance between the powder particles and the solid electrode, and the charging - discharging process of the double layers on the powder particles.