Fabrication and characterization of SiC whiskers toughened Al2O3 paste for stereolithography 3D printing applications

To prevent the agglomeration of silicon carbide whiskers (SiCw) in photosensitive ceramic paste, a butanone-ethanol azeotropic solvent is employed to facilitate the dispersion of alumina particles, SiC whiskers and UV resins. Moreover, SiCw/Al2O3 ceramic pastes, with 5-15 vol % SiCw, are prepared by using ball milling, stirring and distillation processes. The mixture of butanone-ethanol solvent and resins can be effectively separated at 70 degrees C without weakening the polymerization of UV resin. Moreover, an empirical equation is established to evaluate the relationship between SiCw content, aspect ratio and viscosity of resulting ceramic paste. The 15 vol % SiCw/Al2O3 composite ceramic, with SiCw aspect ratio of 50, renders higher resistance to liquid flow and results in a high viscosity of 30,000 mPa s at the shear rate of 30 s(-1). Furthermore, a modified equation is established to predicate the curing depth of ceramic pastes with different amounts of SiCw, where 15 vol % SiCw/Al2O3 composite results in higher light scattering properties, leading to lowest C-d of similar to 0.061 mm. Finally, the complex-shaped SiCw/Al2O3 ceramic component, prepared by SL 3D printing technology, debinding and sintering processes, exhibited a superior fracture toughness of 7.1 +/- 1.20 MPa m(1/2) and a higher hardness of 17.6 +/- 0.78 GPa. (c) 2020 Elsevier B.V. All rights reserved.