Investigation of Additively Manufactured PEEK Modified With Glass Microballons as a Function of Density and Volume Fraction

Abstract

Low density and strong mechanical characteristics make hollow glass microballons (HGM) filled polyehteretherketone (PEEK) composites excellent for aerospace, transportation and civil applications. In this study, PEEK was filled with different densities of HGMs (low, medium, and high) and varied volume fractions (Vf) of HGMs (10%, 15%, and 20%) and exposed to different strain rates to investigate thermal, physical, energy absorption, and other physico-mechanical responses. PEEK/HGMs composites demonstrated a substantial strain rate impact, with the strain rate sensitivity factor increasing as the strain rate increased while decreasing as the filler Vf increased. The density of the composites was also shown to be inversely related to their strength properties. Incorporating high-density HGMs into the PEEK resulted in the lowest composite density so far reported while ensuring mechanical properties. Scanning electron microscopy images revealed that the HGM dispersion is uniform inside the matrix. Thermal stability of the syntactic foam was investigated by using Thermo Gravity Analysis (TGA) under inert atmosphere and oxidative environment conditions. The infusion of microspheres enhances the thermal stability of LDPEs, MDPEs, and HDPEs samples in an inert environment, with HDPEs samples being the most thermally stable. This might lead to the formation of a strong bond between polymer chains and HGM particles.