Fabrication of porous Al2O3 by microwave sintering and its properties

Porous composites of Al2O3/ZrO2 with improved mechanical properties were fabricated by microwave sintering. The microstructure of the composite was characterized by the enhanced neck growth between the initially touching particles. This neck growth was ascribed to the selective heating of ZrO2 between Al2O3 particles in the microwave heating, because of the high dielectric loss factor and good microwave-energy absorption ability of ZrO2. The composite prepared by the microwave sintering exhibited higher elastic modulus and fracture strength than that prepared by conventional sintering. The improved mechanical properties of the microwave-sintered composites were attributable to the enhanced neck growth. (C) 2001 Elsevier Science B,V. All rights reserved.