Direct-ink writing of strong and biocompatible titanium scaffolds with bimodal interconnected porosity

Abstract

Additive manufacturing of porous Ti6Al4V (Ti64) parts is promising for biomedical applications. In this study, Ti64 scaffolds with two scales of interconnected porosity networks were developed using a direct-ink writing process. Inks were made by dissolving a copolymer (Pluronic F-127) in water to obtain a hydrogel, which was then loaded with Ti64 particles. Both Pluronic F-127 amount in the hydrogel and solid loading influenced ink printability, as shown by rheological measurements and printing accuracy investigation. The best compromise was obtained for a 25 wt% Pluronic hydrogel loaded with 50 vol% of Ti64 particles. A partial sintering of 2 h at 1200 ∘C led to interconnected micropores within strut, which was characterised by X-Ray computed tomography. Sintered scaffolds presented a compressive strength higher than bone, with a similar Young’s modulus. According to their biocompatibility, final microstructure and mechanical properties, these scaffolds show a promising potential for load-bearing implants.