Sintered alumina - hard and strong like hot-pressed Al2O3/TiC-composites

Pressureless sintered alumina compacts with high density and with a submicron microstructure are presented with a hardness that approaches or even exceeds the level of advanced hot-pressed Al203 + 35 vol.-% TiC composites; the strength of both ceramics is approximately the same. The investigation of different forming processes shows that quasi-conventional powder processing can be used to produce such outstanding alumina bodies instead of economically problematic sollgel or gel-casting routes. However, powder processing does not only provide advantages in the commercial field but presents major merits in improved properties of the produced bodies: A high homogeneity of the density avoids the typical 1-20 micrometer large pore clusters of submicron sol/gel microstructures. This homogeneity is essential for the production of macroscopic parts with narrow tolerances of mechanical properties.