| Abstract Scope |
Unique process that utilizes AM, preceramic polymer, and chopped carbon fibers precursor to fabricate SiC/C composites has been developed. The study has shown promising, cost-effective, and efficient routes to fabricate complex SiC/C composites using additive manufacturing. A key part of this effort was the mapping of the material’s microstructure through the composite's thickness. Microstructural features, in the pyrolyzed composites through the successive AM layers, such as defects, crystal size, and their distribution, interatomic spacing, and chemical bonds were investigated using HRSEM and HRTEM. Dense and nearly defect-free parts were observed. The CMC displayed three coexisting phases including SiC, SiOC, and C. TEM imaging and XRD showed well-defined SiC and turbostratic carbon features. The cross-sectional mapping of the printed-then-pyrolyzed structures has confirmed consistent structural and chemical features within the internal layers of the AM parts. Noteworthy however is that a crust-like area with high crystallinity has been observed in external layers. |