Influence of Nano-Zirconia on Mechanical and Tribological Behavior of Additively Manufactured Polylactic Acid Composites in Simulated Body Fluid Condition

Abstract

Abstract. Polylactic acid (PLA) has gained much attention worldwide for its applications in the biomedical sector, especially in scaffolds and joint replacements. Various nanofillers have been incorporated into the PLA matrix to improve the mechanical, tribological, and biocompatibility behavior of the polymer. This work discusses the mechanical and tribological behavior of PLA composites reinforced with nano-zirconia prepared via fused filament deposition (FFD). Mechanical properties of the additively manufactured composites were determined by means of tensile testing according to the ASTM standards. Mechanical degradation of the specimens was assessed using in vitro testing of the materials in simulated body fluid (SBF) conditions. The influence of nano-zirconia on the tribological behavior has been analyzed using the pin-on-disc tribometer under SBF lubrication. Results show that the addition of nano-zirconia improved tensile strength considerably. Tribological tests reveal that the addition of nano-zirconia enhances the wear resistance and also reduces the friction coefficient. PLA exhibits adhesion as well as plastic deformation, whereas abrasion and oxidation seem to be the major wear mechanisms involved in the case of PLA composites.