A Zr-Al metallo-organic compound was spray-dried and calcined in air to form ZrO2-Al2O3 hollow particles. The particles were sintered to prepare ZrO2-Al2O3 porous composites. The concentration of the starting solution of spray-drying affected the particle size of the calcined powder and the bulk density of sintered porous ceramics. The porous ceramics have a high fraction of tetragonal ZrO2 and high bending strength, 100MPa.
