Substitution of pure Y2O3 by a mixed concentrate of rare earth oxides (CRE2O3) as sintering additive of Si3N4: a comparative study of the mechanical properties

In this work the substitution of pure yttrium oxide (Y2O3) by a mixed concentrate of yttrium and rare earth oxides (CRE2O3), produced at FAENQUIL-DEMAR, as sinter additive in gas-pressure sintered Si3N4 ceramics has been investigated. CRE2O3 presented similar behavior compared to pure Y2O3 in relation to the sinterability, intergranular phases formed, microstructure and mechanical properties. As this alternative additive is obtained at a cost of only 20% than that of commercial Y2O3, CRE2O3 demonstrated great potential as additive in the sintering of Si3N4 ceramics.