The Corrosion Resistance and Biocompatibility of the Magnetron Sputtered Si Film

In order to address the rapid degradation of biomedical magnesium alloy implants in corrosive media, this study employed a surface modification approach. After fluorination pretreatment of AZ31 magnesium alloy, a silicon (Si) thin film was uniformly deposited on the surface using magnetron sputtering, aiming to enhance the corrosion resistance and biocompatibility of the AZ31 alloy. The corrosion behavior of both coated and uncoated samples in simulated body fluid (SBF) was evaluated through electrochemical tests. Additionally, cytotoxicity and hemocompatibility were assessed using CCK-8 and hemolysis assays, respectively. The results indicate that, compared with the bare magnesium alloy substrate and the magnesium alloy coated with a single sputtered Si thin film, the Si thin film deposited on the fluorinated magnesium alloy substrate exhibits a lower corrosion current density, as well as higher charge transfer resistance, phase angle, and impedance modulus. In addition, the fluorinated Si-coated sample shows lower cytotoxicity. These findings indicate that the combination of fluorination pretreatment and magnetron-sputtered Si thin films is an effective approach for enhancing the early stage corrosion resistance and initial biocompatibility of AZ31 magnesium alloys, providing a promising surface engineering strategy for further investigation.