Effect of passivation and surface treatment of a laser powder bed fusion biomedical titanium alloy on corrosion resistance and protein adsorption

• Published in: Electrochimica acta 2024-01, Vol.475, p.143650, Article 143650
• Main Authors: Nikpour, Saman, Henderson, Jeffrey D., Matin, Sina, Nie, Heng-Yong, Hedberg, Jonas, Dehnavi, Vahid, Hosein, Yara K., Holdsworth, David W., Biesinger, Mark, Hedberg, Yolanda S.
• Format: Article
• Language: English
• Subjects: BSA; Corrosion; EIS; Metal release; Surface analysis
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2023.143650

•Effect of surface finish on corrosion and metal release from Ti6Al4V studied.•Ti6Al4V was produced by laser powder bed fusion using biomedical protocols.•Nitric acid passivation had a negligible effect on metal release and corrosion.•Effect of surface finish (sandblasted, polished) explained by true surface area.•More proteins were adsorbed on rough (sandblasted) surfaces. The biomedical titanium alloy Ti6Al4V has excellent corrosion resistance and biocompatibility and is, therefore, widely used in orthopedic and orthodontic implants. Biomedical implants are increasingly fabricated by additive manufacturing, such as laser powder bed fusion (LPBF). These manufacturing protocols often include sandblasting, surface finish, and passivation. This study aims to investigate the effect of different surface finishes and the commonly used ASTM F86–13 nitric acid passivation for LPBF Ti6Al4V on its corrosion resistance, metal release, and surface changes in benign (bovine serum albumin in a pH 7.4 buffer) and harsh (hydrochloric acid at pH 1.5) solutions using various electrochemical and spectroscopic techniques. Electrochemical, solution and surface analysis showed an insignificant effect of passivation. Smooth surfaces exhibited a slightly better corrosion resistance than rough surfaces due to a 10–20 % smaller true surface area and lower protein adsorption. Implanted ceramic beads from the sandblasting procedure remained on the surface even after the mirror-polishing and passivation procedures. [Display omitted]