Development and Characterisation of Antibacterial Titanium-Copper based Alloys for Additive Manufacturing for Biomedical Applications

Abstract

The development of biomedical implants for dental implants aims to address limitations in strength, biocompatibility and infection prevention. This study investigated the fabrication and optimisation of Ti-6Ta-1.5Zr-0.2Ru-5Cu (mass%) alloy using Laser Powder Bed Fusion (LPBF), focusing on its hardness, microstructural, corrosion and antibacterial properties. The alloy replaces toxic aluminium and vanadium with non-toxic elements while maintaining the same phase proportions and mechanical properties. Ruthenium was added to enhance corrosion resistance and copper was added for its antibacterial properties. Powder atomisation was done using the ultrasound rePowder system to ensure suitability for LPBF. The process parameters were optimised by printing single tracks and assessing their morphology. Subsequently, square samples were printed using the best parameters. The manufactured samples were characterised and compared with as-cast alloys for their microstructure, hardness, corrosion resistance and antibacterial properties. Microstructures were finer for LPBF than as-cast alloys, contributing to enhanced antibacterial properties. However, samples fabricated by both techniques showed similar hardness. Corrosion tests in phosphate-buffered saline (PBS) solution showed good corrosion resistance attributed to the stabilisation of the passive oxide layer, with a corrosion rate below 0.13 mm/year for both techniques. These findings demonstrated the potential of Ti-6Ta-1.5Zr 0.2Ru-5Cu (mass%) alloy as a promising biomedical implant for dental applications.