The strength and hardness of cubic spinel SiAlON (c-Si6−zAlzOzN8−z, z = 1)

The mechanical behavior of the cubic spinel SiAlON polymorph (c-Si6−zAlzOzN8−z, z = 1), was modeled using an ab initio density functional technique. The cubic spinel structure exhibits a maximum stress response of ∼33 and ∼40 GPa, for the applied γ11 and γ23 components of strain, respectively. An existing empirical technique was employed to determine the hardness of the SiAlON crystal: ∼40 GPa. For completeness the hypothesis of the empirical formalism is discussed.