Morphological, mechanical and antibacterial properties of Ti-Cu-N thin films deposited by sputtering DC

Heliyon. 2023 Jun 10;9(6):e17170. doi: 10.1016/j.heliyon.2023.e17170. eCollection 2023 Jun.

Abstract

The problems associated with Stainless Steel 316 L (SS 316 L) orthopedic implants, when implanted in the human body, are infection, local inflammation, and the possibility of bacterial growth. In this study, SS 316 L was coated with copper-doped Titanium Nitride (Ti-Cu-N) using the DC Sputtering technique. This Ti-Cu-N film improved the antibacterial performance and mechanical properties of SS 316 L. The Ti-Cu-N films were deposited using reactive DC sputtering with an 80%:20% argon to nitrogen ratio. The source voltage and current were kept constant at 10 kV and 10 mA, respectively. X-Ray Diffraction (XRD) showed that the phases formed were TiN and Cu with FCC crystal structure. Results show that the surfaces of samples containing 44.34 wt% and 54.97 wt% Cu had antibacterial effectiveness against Staphylococcus aureus (S. Aureus). The highest hardness value of a Ti-Cu-N layer was 212.032 Vickers Hardness Number (VHN), which was an improvement of 36.63% on the raw material (155.18 VHN). Surface morphology analysis using SEM-EDS was performed on the samples before and after the antibacterial test to investigate the antibacterial mechanism of the surfaces of SS 316 L containing Ti-Cu-N against S. Aureus.

Keywords: Antibacterial; DC sputtering; Stainless steel 316L; Titanium nitride.