Corrosion, mechanical and biological properties of biodegradable WE43 alloy modified by Al ion implantation

A high-energy metal vapor vacuum arc (MEVVA) ion source was used to implant aluminum (Al) ions into the WE43 alloy (Al-WE43) at a dose of 1 × 10¹⁶ ions·cm⁻², and the structural composition, mechanical properties, corrosion resistance, and biocompatibility of the alloy before and after implantation were systematically studied. The results showed that an Al₂O₃/Al thin film was formed on the surface of the WE43 alloy after Al ion implantation, and the dense film caused the corrosion current density (I_corr) of the alloy to decrease from 140.2 ± 9.3 to 17.9 ± 6.1 μA⋅cm⁻². Nanoindentation experiments revealed that the elastic model (EIT) and nano-hardness (HIT) of the Al-WE43 alloy were significantly improved due to the surface lattice distortion caused by Al ion implantation. A diluted extract of the Al-WE43 alloy showed higher cell activity, anti-hemolysis and anti-coagulation properties than that of the WE43 alloy. In general, the Al-WE43 alloy can be considered as a promising biodegradable metallic material for cardiovascular stent applications.