Optimization of Compressive Strength Properties in Fused Deposition Modeling 3D Printed PLA/HA Composites for Bone Tissue Engineering Applications

Abstract

This study investigates the optimization of 3D-printed polylactic acid (PLA) and hydroxyapatite (HA) composites for biomedical applications, focusing on enhancing mechanical properties through process parameter optimization and surface modification. The response surface methodology (RSM), along with post hoc statistical validation using Tukey's HSD test, was employed to evaluate the influence of nozzle temperature (200°C–240°C), layer height (0.1–0.3 mm), and HA filler ratio (3–9 wt%) on the compressive strength of both untreated and chemically treated composites. Silane treatment was applied to HA to improve interfacial bonding, resulting in a 5%–7% increase in compressive strength compared to untreated samples. The optimal conditions (240°C, 9% HA, 0.3 mm layer thickness) yielded a maximum compressive strength of 75.35 MPa in treated composites and 71.42 MPa for untreated samples. Statistical analysis confirmed that layer thickness and HA content significantly influenced mechanical performance. Contour plots and 3D response surfaces were also incorporated to visualize parameter interactions. Comparison with other optimization techniques demonstrated that RSM effectively minimized experimental runs while achieving superior mechanical properties. These findings suggest that chemically modified PLA/HA composites are promising candidates for load-bearing biomedical applications.