Layered extrusion forming of complex ceramic structures using starch as removable support

This paper presents a sustainable starch-based slurry that can be used as support material for the 3D printing of complex ceramic parts. The slurry was first prepared by using starch, polyvinylpyrrolidone (PVP), and absolute ethyl alcohol. The rheological properties of the starch-based slurry with different solid loadings, as well as the dimensional deviation rate and bending strength of the green body after drying, were studied. A grid sample was printed to verify its support feasibility, and thermogravimetric analysis was performed to determine the burn loss of the starch-based support material. The results showed that the prepared starch slurry possessed desired rheological and support properties. The size deviation rate of the printed sample was approximately 1.1% after drying, and the bending strength was sufficient (> 11 MPa). Additionally, the drying speed of the slurry was fast, the preparation process simple, and the cost low. The starch support could be completely burned away at 500 degrees C without residue or reacting with the matrix material. The development of this slurry will significantly promote the rapid preparation of complex ceramic components, thereby extending the possibility for a wider application of 3D printing technology in ceramics.