Micro and Nano Structure and Properties of Al₂O₃/TiC Composites

Abstract

High density Al₂O₃/TiC composites were fabricated by a conventional hot-pressing of mixtures of Al₂O₃ and TiC powders at 1700-1900°C in Ar atmosphere. Transmission electron microscopic observations revealed that TiC particles were dispersed not only at grain boundaries but also within Al₂O₃ matrix grains. The mechanical properties of these composites were considerably improved by dispersed TiC particles. The fracture toughness of these composites increased from 4MPam^1/2 to 6MPam^1/2 and the fracture strength also increased from 550MPa to 1100MPa. The effect of TiC dispersions in Al₂O₃ grains on the mechanicai properties such as strength, toughness and hardness were discussed.