SiC-AlN particulate composite

A SiC-AlN composite was fabricated by mechanical mixing of SiC and AlN powd ers, hot pressed under 40 MPa at 1950 degrees C in Ar atmosphere. The objec t of this attempt was to achieve full density and a little solid solution f ormation. Fine microstructure and crack deflection behaviour are to improve the mechanical properties of the SiC-AlN composite. The bending strength a nd fracture toughness were achieved 800 MPa and 7.6 M Pa m(1/2) at room tem perature, respectively. The fracture toughness of the SiC-AlN composite sho ws minimal change between room temperature and 1400 degrees C. Post-HIP imp roves the surface densification of the SiC-AlN composite resulting in an in crease of the strength and the ability, to resist oxidization. The bending strength of SiC-AlN composite increases front 800 to 1170 MPa after HIP tre atment for 1 h under 187 MPa at 1700 degrees C in N-2 atmosphere. (C) 1999 Elsevier Science Limited. All rights reserved.