On the substantial mechanical reinforcement of Polylactic Acid with Titanium Nitride ceramic nanofillers in material extrusion 3D printing

Titanium nitride (TiN) is known as an ultra-hard ceramic, mainly deployed in thin hard coating applications for improving the substrate's surface properties. Therefore, investigating its effectiveness as a reinforcement for thermoplastics in material extrusion (MEX) 3D printing (3DP) has great potential for the development of ma-terials with superior enhancements, which are sought after, as Additive Manufacturing (AM) continuously ex-pands its field of applications. In this study TiN in nano-powder was induced into Polylactic Acid (PLA) thermoplastic and a thermomechanical process was used to produce nanocomposites at various concentrations for 3DP filament. 3D printed specimens using MEX were used for their mechanical characterization and for investigating the thermal, structural, and morphological properties of the nanocomposites. The new materials' performance was evaluated in terms of the TiN filler loading. It was found that Titanium Nitride nanoparticles can upgrade the mechanical response of PLA when used in MEX 3DP. A 43.4% improvement in the tensile strength and a 51.5% enhancement in the flexural strength is reported herein for 4 wt% TiN loading nano-composite. The effect on the process cost from the addition of the filler was also evaluated, indicating that the process is cost-effective with no processability issues.