Investigation of different structures of screw extruders on the flow in direct ink writing SiC slurry based on LBM

Abstract Direct ink writing provides a new method for ceramic material forming. The single-screw extruder is used here to extrude viscous SiC slurry. Because the flow mechanism of ceramic slurry in the slurry direct writing extrusion device is unclear, lattice Boltzmann method (LBM) is used to analyze the flow process of ceramic slurry in the extrusion device. In this study, three different types of special-shaped, single-screw extruders (constant depth variable pitch screw, variable depth constant pitch screw, and variable depth variable pitch screw) are investigated to explore the effects of the shapes on the flow process. Compared with the traditional single-screw extruder, more attention should be paid to the difference in the flow channel. The non-Newtonian rheological model of SiC slurry is built, then the LBM for the non-Newtonian slurry is introduced and used to conduct the simulations based on the aforementioned three different cases. The results show that the effect of constant depth and variable pitch screw on the flow of ceramic slurry is the least and the flow of ceramic slurry in variable depth and variable pitch screw is the most complex.