Preparation and characterization of porous Al2O3 based on nano-Al2O3 powders and PLA template by microwave sintering

Macroporous and mesoporous Al2O3 body was prepared using mesh screening shaped polylactic acid (PLA) template. The mesh screening shaped PLA template was made from 3D cylindrical model by adjusting the PLA filling rate at 30 vol. %. After 3D printing, the PLA template was filled with Al2O3 nano powders and microwave sintered at 1673 K for 20 min. During the sintering, the PLA template was decomposed and left large pores which could promote sintering of Al2O3. The Al2O3 sintered body showed macroporous structure with the pore size of 100 to 300 nm and also mesoporosity with local single crystal structure. The average pore diameter of mesoporous structures in the Al2O3 sintered body was about 7.6 nm. The Vickers hardness of the porous Al2O3 is 1.254 +/- 0.039 GPa. The obtained results confirmed that 3D-printed PLA template assisted microwave sintering is a promising technical processing for the fabrication of macroporous and mesoporous Al2O3 with local single crystal structure.