We present processing (green and sintered), part shrinkage and warping, microstructural characterization, and mechanical properties of Si3N4 made by fused deposition of ceramics (FDC), using optical microscopy, scanning electron microscopy, and X‐ray diffraction. The mechanical properties (fracture strength, fracture toughness, and Weibull modulus) are also reported. Proper FDC build parameters resulted in dense, homogeneous, near‐net‐shape Si3N4, with microstructures and mechanical properties similar to conventionally processed material. Mechanical properties are shown to be isotropic, while there is some degree of microstructural texturing (preferred β‐Si3N4 grain orientation) in sintered components.

The Fused Deposition of Ceramics (FDC) process is an extrusion based layered manufacturing technique. In this study, the microstructural and property homogeneity of GS44-Si3N4 parts made by FDC is examined. The feedstock, green, and sintered parts were examined using characterization techniques such as optical and scanning electron microscopy, x-ray radiography, and x-ray diffraction. In addition, mechanical properties (σf, and Klc), shrinkage, and warpage results were used to characterize the FDC parts. It was found that by using proper build parameters and tool paths, dense, homogenous, near-net-shape GS44-Si3N4 parts can be fabricated. While the mechanical properties of these parts are shown to be isotropic, there is some degree of texturing detected with XRD. Si3N4 filament feedstock intentionally textured with 5.5 vol% of β-seed particles has also been made.

No abstract