The Effect of Magnetron Sputtering Si ₃ N ₄ Coating on the Corrosion Resistance of WE43 Magnesium Alloy

Magnesium and its alloys, despite being lightweight and advantageous for lightweight applications, suffer from comparatively poor corrosion resistance. This study explores the use of surface coatings as a viable strategy to mitigate corrosion rates. A Si 3 N 4 thin film is deposited onto the surface of WE43 magnesium alloy via magnetron sputtering, effectively enhancing its corrosion resistance. The surfaces of the samples are analyzed utilizing scanning electron microscopy (SEM), contact angle (CA) measurements, and X‐ray photoelectron spectroscopy (XPS). Corrosion resistance is assessed using polarization and electrochemical impedance spectroscopy (EIS). Results indicate that the Si 3 N 4 ‐coated magnesium alloy exhibits higher corrosion potential (E corr ) and polarization resistance (R p ), in addition to a decreased corrosion current density (i corr ). Immersion tests reveal that postimmersion in a 3.5 wt% NaCl solution for 24 h, the Si 3 N 4 ‐coated sample only underwent partial erosion by Cl − , without any observable coating delamination. In terms of corrosion resistance, the Si 3 N 4 ‐coated magnesium alloy notably surpasses the WE43 substrate.