Transformative Bioactive Wear Resistant Ti3Au:N and Ti3Au:O Coatings for Medical Implants and Devices

TL;DR

This paper introduces new titanium-gold coatings doped with nitrogen and oxygen that are superhard, wear-resistant, and antibacterial, making them ideal for medical implants and devices.

Contribution

The first demonstration of nitrogen and oxygen-doped Ti3Au coatings with exceptional biotribological and antibacterial properties for biomedical applications.

Findings

Ti3Au:N and Ti3Au:O coatings show wear rates over 20 times lower than Ti-6Al-4V substrates.

The coatings exhibit excellent antibacterial performance comparable to pure copper and silver.

All coatings are biocompatible with leached ion concentrations below 0.2 ppm.

Abstract

Current biomedical implants have high mechanical strength and corrosion resistance, but are highly susceptible to wear and lack antimicrobial properties to fight infection. Here, nitrogen and oxygen‐doped Ti3Au structures are successfully grown with increased dislocation slip plane energy and α‐phase stability for the first time to achieve exceptional biotribological and antibacterial performance. The new Ti3Au:N and Ti3Au:O coatings are grown on Ti‐6Al‐4 V substrates via magnetron co‐sputtering of Ti/Au in Ar:N2 and Ar:O2 environments at 450 °C and characterized for structural, chemical, tribomechanical, biocompatibility, and antibacterial properties. The reactive gas environments produce highly crystalline Ti3Au:N and Ti3Au:O coatings containing α‐Ti3Au phases, with partial columnar structures. All coatings present extremely safe cytotoxicity profiles with leached ion concentrations <0.2 ppm, and antibacterial performance like pure Cu and Ag, with a drastic reduction in bacterial colonies within 20 min of exposure. Nitriding and oxidizing the Ti3Au coating produces superhard scratch‐resistant surfaces with wear rates >20 times lower than the Ti‐6Al‐4 V substrate. The findings demonstrate new biocompatible Ti3Au:N and Ti3Au:O coatings with outstanding multifunctional biotribological and antibacterial properties with the potential to significantly extend the lifetime of medical implants and devices, such as joint replacements, bone screws, and surgical devices.

Coatings of titanium‐gold are grown in nitrogen and oxygen environments via magnetron sputtering to simultaneously enhance their biotribological and antibacterial properties. The coatings are highly crystalline with superhard scratch‐resistant surfaces and wear rates 20 times lower than the bare Ti‐6Al‐4V substrate. All coatings present excellent biocompatibility and antibacterial performance like pure Cu and Ag.

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