Electric pulse assisted rapid consolidation of ultrafine grained alumina matrix composites

The densification of alumina is influenced by the electrical pulse and the starting crystal structure of alumina powder. The application of electric pulsing enhanced the densification and the level of enhancement depended on the pulsing sequence. A pure alumina specimen with > 98% theoretical density was obtained in less than 10 min at 1573 K. The average grain size was similar to 0.7 mu m. Similar sintering parameters were used to synthesize alumina based nanocomposites with > 99% theoretical density in 5-10 min sintering times. The electric pulse and pressure assisted sintering is a very effective way to synthesize nanocomposites in a short sintering time at lower temperatures. (C) 2000 Elsevier Science S.A. All rights reserved.