Improved Antibacterial Properties of Additively Manufactured Ti–6Al–4V Surface Machined by Wire Electro-Discharge Machining

Abstract

Titanium alloys are the most demanded material type in implant applications. However, developing bacteria-resistant implant characteristics is still in the progress of the research field. In this study, the performance of micro-wire electro-discharge machining (μ-WEDM) surface modification technique on Ti–6Al–4V alloy is investigated. The performance parameters such as material removal rate, kerf width, surface roughness, and crater size are evaluated in terms of capacitance and gap-voltage input parameters. In addition, the adhesion of bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Bacillus subtilis on treated surfaces is tested. Results show that the difference in discharge energy affects surface biofilm prevention performance. According to that, Pseudomonas aeruginosa, Escherichia coli, and Bacillus subtilis attach more on surfaces with 0.727 μm roughness which are machined with 10 nF and 100 V. Staphylococcus aureus attaches more on surfaces with 0.211 μm roughness machined with 1 nF and 90 V. Meanwhile, surface with 1.531 μm roughness, machined with 100 nF and 110 V, provides the least number of bacteria attached to the surface for all strains except Bacillus subtilis. In conclusion, this study found that μ-WEDM surface treatment techniques can increase biofilm prevention properties of implant surfaces for different bacteria strains, within a certain range of discharge energy.