Mechanical and thermal characterization of nanoparticle-reinforced polymer scaffold structures produced by stereolithography (SLA) method

Additive manufacturing methods are a manufacturing technology that performs production in successive layers with polymers, metals, ceramics, composites and similar materials based on computer-aided design (CAD) models. Unlike traditional manufacturing methods, additive manufacturing processes offer a more sustainable manufacturing approach by minimizing material waste. Stereolithography (SLA), which is among these methods, is based on the principle of hardening liquid photopolymer resin layer by layer using a light source. The SLA method is quite advantageous in the production of components with complex geometries and fine details due to its high surface quality, great accuracy and precision. In this study, the morphological, mechanical and thermal performances of lattice structures and samples produced by SLA method by doping with Al₂O₃, hBN and SiC nanoparticles were investigated. Octahedral, simple cubic and diamond shaped lattice structures along with tensile and impact samples were produced using a UV curable photopolymer resin. Thermogravimetric analysis (TGA), derivative thermogravimetric analysis (DTG) and differential thermal analysis (DTA) were performed to evaluate the performance of different material and structural combinations; also tensile, compression and Charpy impact tests were applied. The results showed that hBN reinforced samples had the highest tensile strength and thermal stability, while Al₂O₃ addition significantly increased the impact resistance. In contrast, SiC addition led to a decrease in ductility and lower thermal resistance. Among the lattice structures, the simple cubic design exhibited the highest compressive strength, while diamond structures provided a balanced performance in terms of hardness and ductility. Scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) analyses revealed that the nanoparticles were homogeneously distributed in the matrix and the structural integrity was preserved.