Effect of Aluminum Oxide Powder Particle Size on Spark Plasma Sintering Results

Abstract

The results of a comparative study of compacts obtained by spark plasma sintering from nano- and ultradisperse (UD) aluminum oxide powders with spherically shaped particles are reported. It is shown that the compacts obtained from UD-powder have higher density and greater strength, microhardness, and structural uniformity with smaller grains than compacts obtained from nanopowder. Preliminary magnetic-pulse compaction of powders prior to sintering improves the characteristics of both compacts but higher density and strength with smaller grains are achieved in compacts obtained from UD-powder. In both cases of preliminary preparation the UD-powder compacts have advantages over nanopowder compacts.