| Abstract Scope |
Preceramic polymers have received considerable attention recently as potential feedstock materials in additive manufacturing (AM) technologies. They offer some advantages over conventional ceramics, including lower processing temperature, tailorable chemical composition, and opportunities for UV curing that are central to some AM technologies. However, the polymer-to-ceramic conversion is associated with dimensional shrinkage and off-gassing of organic species present in the polymer that can lead to porosity and cracking in polymer-derived ceramics, particularly those having thick sections. This talk will explore the size effects that arise in polymer-derived ceramic composites fabricated by material extrusion AM by characterizing the porosity, cracking, and flexural strength of two different formulations of zirconium diboride-reinforced polysilazane through the printing, curing, and pyrolysis process. Results show that using an alumina nanoparticle viscosifyer improves the printing behavior of the ink while also reducing the porosity and increasing the flexural strength and Weibull modulus of the pyrolyzed composite. |