Elastic constants of zirconia single crystals determined by X-ray measurements for polycrystals

Abstract

A previously developed method for determining elastic constants of single crystals from polycrystalline specimens was applied to cubic and tetragonal zirconia. The method is based on the orientation dependence of the lattice strain of a stressed specimen as measured by X-ray diffraction and also on Kröner's equation relating the elastic constants of polycrystals to those of a single crystal. A simple loading device for a disc-shaped specimen was developed using a Ti-Ni shape memory alloy. The resulting elastic constants, C11, C12, and C44 for cubic zirconia were in fair agreement with those measured directly on a single crystal. The same method was applied to tetragonal zirconia after verifying that the elasticity of this material may be well approximated by cubic symmetry. Error analysis and suggestions for an improved measurement are also included.