Cu-doped TNTZ thin films for biomedical applications
2nd International Conference on Applied Surface Science (ICASS), 12-15 June, Dalian, China
Research on the β-type titanium alloys containing non-toxic elements and non-allergic properties has increased rapidly during the past decade. The objective of our research work is to study the effect of copper on Ti-Nb-Ta-Zr (TNTZ) sputtered uniform/adhesive thin films. TNTZ-Cu thin films (1-2 µm) were DC magnetron co-sputtered from an alloying target Ti-23Nb-0.7Ta-2Zr (at.%) and a pure Cu target. These films contained amounts of copper varying from 4 to 18.6 at.%. An experimental study was carried out to characterize the physico-chemical properties of the samples’ surfaces by EDX, SEM, AFM, XRD and nanoindentation. The bactericidal activity of coatings was evaluated by inductively coupled plasma mass-spectrometry (ICPMS–MS). The films deposited were chemically homogenous and the columnar morphology of TNTZ-Cu films was due to the high deposition pressure in the magnetron chamber. The film roughness evaluated by atomic force spectroscopy (AFM) on the TNTZ-Cu 8.3 at.% Cu sample presented an RMS-value of 20.1 nm being the highest RMS of any Cu-sputtered TNTZ sample. These films with a copper content of 8.3 at.% showed the fastest bactericidal activity. The XRD spectrograms of TNTZ-Cu films showed that the films were single phased with the β-Ti BCC structure. The nanoindentation measurements showed that Young’s modulus (E) and hardness (H) of films varied respectively in the range 77–104 GPa and 3–6.4 GPa by increasing Cu content up to 18.6 at.%. E and H decreased to a copper content of ∼7%, and increased above. It seems that formation of an amorphous phase leads to increasing mechanical properties. The antibacterial performance of these innovative TNZT-Cu coatings suggests a potential application in hospitals, health care facilities, implants, schools and public places.