Grain boundary analysis in superplastic sio₂ - doped TZP

Detailed grain boundary analysis in superplastic SiO₂-doped tetragonal zirconia polycrystal (TZP) is performed using high-resolution electron microscopy (HREM) and energy-dispersive X-ray spectroscopy (EDS). As a reference, high - purity TZP is also investigated. In SiO₂ - doped TZP, an amorphous SiO₂ phase is present only in grain junctions and not in the grain boundary faces. But it is found that Si⁴⁺ ions are distributed along gram boundaries with thickness of several nanometers. Y³⁺ ions are segregated in grain boundaries in SiO₂ - doped TZP as well as high - purity TZP. The ductility enhancement in SiO₂ - doped TZP must be understood from the detailed knowledge on grain boundary structure and chemistry.