Plasma modified Mg–Nd–Zn–Zr alloy with enhanced surface corrosion resistance

•Mg alloy is modified by C2H2 plasma immersion ion implantation and deposition.•The enhanced corrosion resistance is due to the formed diamond-like carbon film.•The corrosion mechanism is discussed from the perspective of random defects.

Plasma immersion ion implantation and deposition (PIII&D) is conducted to modify the corrosion behavior of Mg–Nd–Zn–Zr alloy. A diamond-like carbon film (DLC) with a thickness of about 200 nm is formed on the surface after acetylene PIII&D and the resulting corrosion resistance in the 0.9 wt% NaCl solution is significantly improved. The corrosion mechanism is discussed from the perspective of random defects in the DLC film.