Size-dependent mechanical behaviors of cubic-phase yttria-stabilized zirconia

The polycrystalline yttria-stabilized zirconia (YSZ) used in many industrial applications usually possesses micron-sized grains in cubic phase. However, mechanical properties and deformation mechanisms of cubic-phase YSZ at such small scales remains almost unknown to date. Herein, the mechanical properties and deformation mechanisms of cubic-phase YSZ under compression at different scales are investigated through in situ micropillars compression and indentation experiments combined with molecular dynamics (MD) simulations. Our work reveals that the yield strength and Young's modulus of YSZ at the microscale are much smaller than those of its bulk counterpart. In addition, the failure of micron-sized YSZ under compression is mainly due to slipping, while, besides slipping, cracking also occurs in the bulk structure of YSZ. This study expands current knowledge of mechanical behaviors of small-scale cubic-phase YSZ, which can provide valuable guidance for the microstructure design of YSZ materials to enhance their mechanical performance.