Electrostatically assembled SiC–Al2O3 composite particles for direct selective laser sintering

In the advancement of directed energy deposition, 3D printing technology has been undergoing revolutionary changes, especially in metal and polymer printing technology. On the contrary, the 3D printing of ceramics has not experienced such rapid development due to their requirement for high-temperature sintering and inferior energy adsorption property, limiting their use in application such as direct selective laser sintering (SLS). In this study, a novel controlled fabrication of composite powders consisting of silicon carbide (SiC) and alumina (Al₂O₃) was developed for fundamental investigation in direct SLS using an infrared laser radiation with a wavelength of 915 nm. Improved laser absorbance and a plausible way to reduce volume shrinkage during the sintering process are demonstrated through the control of composite particles formation. The composite particles were designed using a bottom-up approach via an electrostatic nano-assembly method at room temperature. Although further finetuning is still indispensable prior to practical applications, the findings of this work will provide a vital platform for powder modification and advanced powder development for ceramic materials fabrication through directed energy deposition route.