Electrochemical corrosion behavior study of different porosity zinc scaffolds in simulated body fluid (SBF) for biomedical applications

The goal of the current work is to analyse the Zn scaffold porosity effects on its corrosion behavior. Organized porous network structure (OPNS) zinc samples with varying porosity were manufactured by a newly developed rapid tooling approach that combined 3D printing and microwave sintering. The outcomes of the OPNS Zn samples were also compared to the dense zinc sample. For the corrosion analysis, porous and dense zinc samples electrochemical corrosion testing were conducted in SBF electrolyte at 37 degrees C. The zinc samples morphological study was accessed by scanning electron microscopy (SEM). It was confirmed by the findings of the morphological study that the Zn samples contained randomly distributed micropores and designed or organized macropores. The zinc sample corrosion behavior in SBF was analyzed by potentiodynamic (PD) polarisation and electrochemical impedance spectroscopy (EIS) curves. In addition, an electrical equivalent circuit (EEC) model was developed using the EIS experimental data to establish an understanding of the corrosion behavior of Zn samples. Overall corrosion testing results demonstrate that the diffusion mechanism had an impact on the corrosion mechanism of Zn samples and diffusion mechanism during electrochemical reaction supported by the porosity of the sample. The Zn samples corrosion rate was found to be minimum for the dense sample (0.14 mm y-1), while it was maximum for the highest porosity OPNS Zn sample (0.66 mm y-1). The present study corrosion rate of Zn samples was comparable with the required value for bone implants.