Hollow Glass Sphere Modification Effect on Mechanical Properties of Powder Bed Fusion Processed Polyamide 12 Parts

Abstract

This study investigates the effects of modifying PA12 powder with a low concentration of surface-functionalized hollow glass spheres on powder characteristics and the mechanical properties of the Powder Bed Fusion–Laser Beam (PBF-LB) produced parts. A novel and scalable feedstock formulation was developed using a dissolution-precipitation method followed by dry mixing, which enabled the uniform incorporation of hollow glass spheres (Glass Beads (GBs)) while preserving the powder's flowability and thermal behavior. The powders were characterized by morphology, particle size distribution, flowability, melt behavior, and sintering window. After PBF-LB processing, the as-built parts were analyzed for part density, surface roughness, tensile, flexural, and impact properties. Results indicate that GB modification did not adversely affect powder quality but altered the mechanical performance of printed parts. 1 wt.% glass bead modified PA12 parts exhibited lower relative density and tensile strength compared to virgin PA12, but showed significantly enhanced impact resistance. This improvement is attributed to energy-absorbing mechanisms enabled by strong interfacial bonding between the glass beads and the PA12 matrix. This work introduces a novel toughening strategy for PBF-LB polymers, contributing a new material design pathway for producing lightweight, impact-resistant components in additive manufacturing for aerospace, automotive, and consumer applications using PBF-LB processes.