Investigating mechanical properties of sintered ZnGa2O4 ceramics using nanoindentation

Abstract

The role of sintering on the microstructure and mechanical properties of ZnGa2O4 pellets has been systematically investigated in this work. The hardness (H) and elastic modulus (E) of the sintered pellets are obtained via quasi-static and dynamic nanoindentation. The force versus displacement curves revealed the elastic-plastic behaviour of the ZnGa2O4 ceramics. The H and E values of the sintered pellets vary within 5.29–3.94 GPa and 149.25–111.04 GPa, respectively. A decreasing trend is observed in both H and E of the sintered pellets with increased sintering duration which could be ascribed to the grain size of the sintered products. In addition, the viscoelastic properties of the sintered ZnGa2O4 ceramics were examined via dynamic nanoindentation. The results from the dynamic nanoindentation testing revealed that ZnGa2O4 ceramics show the reverse indentation size effect (RISE). Further, a high storage modulus of 121 GPa was obtained with a corresponding low damping factor. Thus, the above investigations not only provide a new insight into the microstructural and mechanical properties of ZnGa2O4 spinel but also open avenues for its wider commercial applications.