Substitution of Y2O3 by a rare earth oxide mixture as sintering additive of Si3N4 ceramics

The objective of this work was to compare the sinterability, the microstruc tures and the mechanical properties of Si3N4 ceramics with additive mixture s based on yttrium oxide, Y2O3, and a mixed concentrate of yttrium and rare earth oxides. The RE2O3 samples were prepared by a two-step gas-pressure s intering process. No significant differences between the samples have been found, thus demonstrating the potential of this low cost alternative sinter additive. (C) 2000 Elsevier Science B.V. All rights reserved.