Influence of Processing Parameters on the Mechanical Properties of 3D Printed Borosilicate Particulate Reinforced Polymer Composites

Emerging composite materials are expanding the potential of additive manufacturing and enabling applications previously restricted by traditional manufacturing methods through their multi-phase nature and complex internal geometry. Additionally, these materials can be pyrolyzed to create dense metal, ceramic, and glass parts with geometries typically not achievable by traditional processes. Additive manufacturing of borosilicate glass composites can enable new applications in nuclear engineering, astronomy, and bone regrowth therapy. To elucidate the process–parameter relationship of borosilicate–polylactic acid (PLA) composites, mechanical test specimens were fabricated by fused-filament fabrication and compared with a pure PLA baseline. Optical and scanning electron microscopy were conducted to observe the specimen microstructure before and after testing. From the stress–strain curves, the highest compressive yield strength for the composite was 28.22 MPa, and the highest compressive yield strength for PLA was 49.30 MPa. Print orientation was found to benefit the composite material but have a detrimental effect on the pure matrix material. Borosilicate–PLA with 100% infill, 1 shell wall, and layer lines parallel to compression axis had an elastic modulus of 2.66 GPa. Microscopy revealed that lower-modulus composite specimens had the particulates re-distributed within the matrix. Tensile testing was done according to a polymer testing standard, which caused difficulties obtaining consistent fracture within the gauge length.