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
microstructures and the mechanical properties of Si3N4 ceramics with
additive mixtures 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 sintering process. No significant differences
between the samples have been found, thus demonstrating the potential
of this low cost alternative sinter additive.