Coating post-processing treatment for material extrusion 3D-printed Al2O3-based ceramic

Material extrusion three-dimensional (3D) printing is an additive manufacturing technique for printing 3D models of complex structures. Ceramic parts can be produced layer by layer by extruding viscoelastic slurries through precision nozzles. However, lamination inevitably occurs during the extrusion process, which reduces the surface precision of the ceramic parts. Therefore, we developed a coating material and corresponding coating process to improve the surface accuracy. The surface roughness (Ra) of ceramic parts decreased from 12.5-30μm to 3.2-6.3μm by coating post-processing treatment. Further, the coating was firmly bonded with the substrate and that the coating did not crack and fall off at 1500 ℃. Finally, the ceramic shell after coating was poured with metal liquid, and the metal castings with good surface accuracy were obtained. This study demonstrates the improved surface accuracy of ceramic parts prepared by extrusion 3D printing and expands the application range of extrusion 3D printing technology.