Electrically conductive gelcast porous alumina sintered under argon atmosphere

Electrically conducting porous ceramics have gained a recent surge of interest in the development of high performance radiant heaters for the oxidation of noxious emissions, and others. This paper describes a simple and direct approach for introducing an electrical conductive phase into insulating porous alumina by gelcasting of mechanically foamed slurry, followed by inert sintering. The amount of monomer in the mechanically foamed slurry was varied with sintering in argon atmosphere. The electrical resistivity was measured using the van der Pauw's method. Results showed increasing monomer additions significantly affecting the lowering of electrical resistance, which measured at about 1.15 Ω-cm to 0.32 Ω-cm. The increase in temperature of the sample over increasing current as well as under microwave supported that this material is a potential porous heater in the oxidation of hazardous emissions, and absorber for electromagnetic waves. Further tests were conducted such as X-ray diffraction, TGA, and I– V plot that were used to describe the electrical conductive behavior of the material.