Preparation and properties of porous alumina with inter-locked platelets structure

Abstract

Porous alumina ceramics with alumina platelets was prepared by vapor-solid reaction sintering of AlOF mesophase gas by the reaction of HF and Al2O3. The effect of heating treatment temperatures on porosity, the formation of inter-locked platelets structure and compressive strength of porous alumina ceramics was determined by Archimedes' method, XRD, SEM and compressive tests. The results indicated that after heating at temperatures from 1300 °C to 1600 °C, the porosity of alumina ceramics decreased from 61.6% to 48.4%. Increasing the heating treatment temperature was beneficial to form inter-locked structure between alumina platelets. The maximum compressive strength of porous ceramics with porosity of 48.4% can reach 29.8 MPa heated at 1600 °C; this strength was attributed to the strong bonding between the alumina platelets.