Tailoring mechanical properties of FDM-3D-printed parts through titanium dioxide-reinforced resin filling technique

Fused deposition modeling (FDM) is a type of additive manufacturing that falls under the category of material extrusion. Building an object using FDM involves layer-by-layer selective deposition of melted material along a predetermined path. However, FDM parts are inherently anisotropic, meaning their mechanical properties vary depending on the direction of loading, which makes them prone to failure under transverse loads. This study introduces a novel post-processing technique to enhance the mechanical properties of FDM parts. Unlike conventional FDM printing, this study explores a post-processing technique where TiO 2 -infused resin is injected into the internal voids of printed parts to reinforce their structure. Compared to unfilled counterparts, resin filled structures exhibited significant improvements in tensile strength (up to 40%) and impact energy (up to 28%). A 20% infill density was found to offer a cost-effective balance between material usage and performance, while 2% wt. TiO 2 achieved the optimal balance between reinforcement and dispersion, exceeding the performance gains of other concentrations. SEM analysis confirmed effective TiO 2 dispersion at lower concentrations, leading to smoother surfaces and potentially improved mechanical properties. This technique presents a promising approach for fabricating high-performance FDM parts with enhanced strength and toughness.