The mechanical behavior of fully yttria-stabilized zirconia was investigated by means of nano-indentation. Coarse- and fine-grained materials had a similar reduced modulus and hardness. A clear pop-in was observed in coarse-grained material, with the pop-in loads varying with grain orientation and distance from the grain boundary. The pop-in was not clear in nanocrystalline material. A lower hardness of the grain boundary, and the similar hardness values of the two differently grain-sized materials, indicated the existence of an intrinsic atomic structure difference in the coarse- and fine-grained samples.

Grain Size and Grain Boundary Effects on the Mechanical Behavior of Fully Stabilized Zirconia Investigated by Nanoindentation. J.Lian, J.E.Garay, J.Wang: Scripta Materialia, 2007, 56[12], 1095-8