Speaker
Description
Implant-associated infections caused by bacterial biofilms represent a serious clinical problem. Being highly resistant to conventional antibiotic treatments, it becomes urgent to find new solutions to tackle this form of infection, such as innovative materials with effective antimicrobial properties.
Binary TiNb alloys are promising implant materials due to their low stiffness, excellent corrosion resistance and biocompatibility. We added small amounts of Ga, which has bactericidal activity and prevents biofilm formation.
The aim of this work is to study, experimentally and theoretically, the structural, mechanical and electronic properties of novel beta-type TiNbGa alloys (with a Ga content less than 8 wt.%) produced by cold crucible casting. The influence of Ga content on the atomic arrangement of the elements, the elastic and electronic properties is studied by a combination of experimental methods (X-ray diffraction, SEM-EDX, non-destructive ultrasonic studies, microhardness) and ab-initio calculations (DFT) performed in parallel.
Experimental and theoretical results are compared according to the proportions of elements involved. It is shown that the beta-cubic phase is preserved up to 8% by weight of Ga, an alpha stabilizer. Electronic structure analysis allows us to emit the least energetically favorable structure according to the topography of the TiNbGa systems revealing preference for TiGa first neighbours. A lattice parameter decrease with increasing Ga content is found experimentally and theoretically confirmed. Gallium introduces well localized d-electron states while its s-electrons present anti-bonding hybridizations with Ti and Nb neighboring atoms around -7 eV, similarly to TiNbSn and TiNbIn cases.
This study sets up a method (numerical and experimental) for the development of novel low-modulus and potentially antibacterial Ga-bearing beta-titanium alloys.
This project received funding from the EU’s Horizon 2020 research and innovation programme under the MSCA grant agreement No. 861046 (BIOREMIA ETN).
| Speaker Country | Italy; France |
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