Mechanical property improvement and microstructure observation of SiCw-AlN composites

SiCw-AlN composites were produced with different sintering additives. Eight wt% Y2O3 was found a suitable sintering additive for mechanical property improvement of SiCw-AlN composites. With the sintering additive, SiCw-AlN composites with whisker content ranging fr om 10-30 wt% were hot-pressed to high density, and the flexural strength and fracture toughness were significantly improved with the increase of SiC whisker content. SEM and TEM observation indicated that several kinds of toughening mechanism contributed to the increasing toughness, including crack deflection, crack branching and whisker bridging process. The interfacial boundaries of the composites were also discussed in detail. (C) 1999 Elsevier Science Limited. All rights reserved.