The effect of non-stoichiometry on microstructure and selected properties of YAG polycrystals

Using modified citrate process three materials were prepared: the one of stoichiometric Al/Y ratio corresponding to YAG composition, another one with aluminum deficit and the third one containing surplus amount of aluminum. Typical microstructure of single-phase body reveals stoichiometric material. The one of aluminum deficit shows YAP inter-crystalline inclusions. Material of Al/Y ratio higher than the YAG stoichiometry shows inter/intra α-Al2O3 inclusions. Stoichiometry of the system influences mechanical properties of the material.