Investigation on corrosion behavior of WE43 Mg alloy for biomedical applications through magnetron sputtered coatings

Abstract WE 43 Magnesium alloy is an advanced and promising candidate for orthopaedic biomaterials due to its biocompatibility, degradability and good mechanical properties. However, its high corrosion rate in the physiological conditions leads to a loss of mechanical integrity before the bone tissue has a chance to heal (ex. bioabsorbable interference screws). This study investigates this challenge by applying a Pure Titanium (Ti) coating on a WE 43 Mg alloy via a magnetron sputtering process. The objective was to investigate the influence of the Ti coating on the alloy’s microstructure, and initial electrochemical corrosion response. Material characterization was performed using FESEM, AFM, and PXRD. Corrosion properties were studied using a potentiodynamic analysis. The results indicated that the Ti coating significantly improved the corrosion resistance, reducing the corrosion rate from 7.66 mm/year (Uncoated sample) to 2.93 mm/year (Coated sample). The Ti coated material also showed a contact angle of about 83° whereas the uncoated sample showed about 75°, indicating a reduction in surface wettability (increased hydrophobicity). These findings indicate that a Ti coating on WE43 Mg alloy can effectively enhance its initial electrochemical corrosion resistance, which is critical for potentially improving implant longevity in biomedical applications.