TIC-STRENGTHENED AL2O3 BY POWDER TAILORING AND DOPING PROCEDURES

High-carbide Al2O3/TiC composites have been fabricated without hot-pre ssing by different processing techniques. Transient liquid phase sinte ring with additions of TiH2 turned out to be the most promising of the doping procedures. The highest strength, (> 800 MPa), however, was me asured when omitting all additives and using a tailored alumina raw ma terial with narrow grain size distribution. The influence of the alumi na grain size distribution on sintering and strength is discussed as b eing associated with the amount of grains and aggregates larger than 1 mum and with the mutual homogenization of oxide and carbide component s. In contrast, the reduction of the median powder grain size plays a minor role only.