Titanium Nitride Coatings on CoCrMo and Ti6Al4V Alloys: Effects on Wear and Ion Release

While titanium nitride (TiN) coatings are well known for their biocompatibility and excellent mechanical properties, their wear particle and debris release in orthopedic implants remains a matter of active investigation. This study addresses the efficacy of TiN coatings on CoCrMo and Ti6Al4V alloys to enhance wear resistance and reduce ion release from prosthetic implants. Three different coating variants were utilized: one variant deposited using arc evaporation (Arc) followed by post-treatment, and two variants deposited using high-power impulse magnetron sputtering (HiPIMS) with or without post-treatment. The coatings' performance was assessed through standard wear testing against ultra-high-molecular-weight polyethylene (UHMWPE) in bovine serum lubricant, and in the presence of abrasive PMMA bone cement particles in the lubricant. The results indicated that Arc and HiPIMS with post-treatment significantly reduced wear and eliminated detectable metal ion release, suggesting that these coatings could extend implant longevity and minimize adverse biological responses. Further long-term simulator and in vivo studies are recommended to validate these promising findings.