Degradation Behavior of Zn–Cu Stents with Different Coatings in Sodium Chloride Solution

The Zn0.6Cu wires are fabricated into stents for the potential biodegradable application of nasal wound healing. The degradation behavior of Zn0.6Cu stents in 0.9 wt% NaCl at 36.5 °C is evaluated. It shows that the untreated Zn0.6Cu stent experiences severe crevice corrosion with acceleration and autocatalytic effects within the micro-cracks and ruptures at 4.67 ± 1.15 d, with the average corrosion rate of 0.28 mm y⁻¹. Fortunately, the anodic polarization (AP) + hydrothermal (H) conversion coating, consisting of ZnCO₃, Zn(OH)₂ and ZnO, could inhibit the crevice corrosion significantly by reducing the cathode/anode ratio, extending the rupture time up to 16.50 ± 2.95 d, with the average corrosion rate of 0.14 mm y⁻¹. This research indicates that the biodegradable Zn-based stent has some potential applications in nasal wound recovery area.