Fabrication of hollow lattice alumina ceramic with good mechanical properties by Digital Light Processing 3D printing technology

In this study, two configurations of alumina (Al2O3) ceramics (hollow lattice structure and solid lattice structure) were prepared by DLP 3D printing technology. When sintered at 1600 degrees C for 4 h, dense alumina ceramics with an average grain size of 4.38 +/- 1.26 mu m can be obtained. The Al2O3 ceramics prepared by DLP process have good forming precision and shape. The dimension error can be controlled about 0.2 mm. The compressive strength of solid block is 572 MPa. The maximum compressive strength of solid lattice (2.0 mm in diameter and 45% in porosity) is 9.70 MPa. The maximum compressive strength of hollow lattice (2.0 mm in diameter, 0.3 mm in thickness and 70% in porosity) is 4.30 MPa. The thermal simulation results show that the temperature of the hollow lattice (diameter 1.2 mm, porosity 76%) with 500 degrees C upper surface transferring to the lower surface is only 88.6 degrees C, which is lower than 133 degrees C of the solid lattice. Hollow lattice structure can effectively reduce heat loss and improve energy efficiency. The hollow lattice structure Al2O3 ceramics formed by DLP technology is expected to be used in industrial thermal insulation applications.