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 symbolscript 1016 symbolscript 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 im-plantation, and the dense film caused the corrosion current density (Icorr) of the alloy to decrease from 140.2 symbolscript 9.3 to 17.9 symbolscript 6.1 symbolscript 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.