Densification and Mechanical Properties of 4AIN-SiC Ceramics -Utilization of Nanocomposite Powders Prepared by the Nitridation of Aluminum Silicon Carbide-

The densification behavior of aluminium nitride (AlN)-silicon carbide (SiC) composites has been examined using a nanocomposite powder. The starting powder with average particle size of approximately 100 nm, whose chemical composition corresponded to 4AlN-SiC, was prepared by the nitridation of aluminum silicon carbide (Al4SiC4) at 1500 °C for 3 h. The relative density of the 4 AlN-SiC composite ceramic with sintering aid (6 mass%Al2O3 and 4 mass%Y2O3)hot-pressed at 1900 °C for 1 h was 93.5 %; the average grain size was as small as 1,3 um, which was about one-third as large as that using commercially-available AlN and SiC powders. The Vickers hardness and flexural strength of this composite were 19.2 GPa and 469 MPa, respectively.