Plasma Immersion Ion Implantation for the Prevention of Metal Ion Release From CoCrMo Alloys

Surface modifications of biomaterials by plasma immersion ion implantation (PI3) are innovative methods to improve the biocompatibility of these materials. In this paper, the modification of the ion-releasing behavior of a LC forged ASTM F-799 CoCrMo alloy after implantation with N and O in a plasma immersion ion implantation process is described. Corrosion behavior in bovine serum was measured by open circuit potential and cathodic potentiodynamic polarization curves. After corrosion tests, metal ion release was estimated comparing GDOES analysis results in treated samples before and after corrosion tests. They showed a good relation between both studies. Better results in corrosion tests indicate important reduction in Co and Cr ions release rates. Conclusions about corrosion improvement of CoCrMo alloys after N or O implantation are presented.