Comparative analysis and optimization of nanoalumina, nanosilica, and nanozirconia reinforcements in 3D-printed PLA composites

This study investigates the mechanical and tribological performance of seven different PLA-based composite formulations reinforced with nanoalumina, nanosilica, and nanozirconia at weight fractions of 0, 3, and 6%. A multi-criteria decision-making approach, namely the Preference Selection Index (PSI) method, was employed to evaluate and compare the relative effectiveness of the reinforcements and to identify the optimum nano-filler. The evaluated performance attributes included physical properties (void content and water absorption), mechanical properties (hardness, compressive strength, and flexural strength), and wear behavior. The results indicate that the incorporation of 3 wt.-% nanoalumina led to increases of 18%, 29%, 9%, 3.3%, 3.6%, and 11.7% in void content, water absorption, hardness, compressive strength, flexural strength, and impact strength respectively. Similarly, the addition of 3 wt.-% nanosilica resulted in increases of 43%, 5.8%, 27%, 5%, 5.4% and 23%, while 3 wt.-% nanozirconia enhanced these properties by 7.8%, 14%, 13%, 8.3%, 7.2%, and 41%, respectively. Based on the PSI optimization considering all evaluated attributes, nanozirconia was identified as the most effective reinforcement, followed by nanoalumina and nanosilica.