Mechanical performance of lightweight ceramic structures via binder jetting of microspheres

Abstract

Geometrically-complex and lightweight ceramic parts manufactured via 3D printing are prospective structures that seem to provide excellent thermal, wear and dielectric performance. In the present work, binder jetted parts based on synthetic lightweight ceramic hollow microspheres were manufactured and evaluated under different testing conditions in order to characterize their mechanical performance. The resulting structures were assessed in terms of quasi-static flexural and compressive strength, and density. Furthermore, microscopy analyses highlighted the composition of the final structures and fracture mechanisms. The printed system mainly consisted of aluminum silicon dioxide, fly ash and traces of metal. The samples yielded similar strength as that achieved on conventional bulk-based 3D printed ceramic structures. It was observed that the strength of the printed microspheres increased by sintering the parts to near-fusion temperatures due to viscous flow of material during sintering. The combination of the proposed process and feedstock represents an attractive manufacturing method for fabricating lightweight structures for applications like composite tooling molds, electromagnetic devices, and biomedical implants.