Analysis of grain boundaries in a fine-grained, superplastic, Yttria-containing, tetragonal zirconia

The microstructure and chemistry of grain boundaries in a superplastic Y-TZP (ZrO sub 2 --5.2 wt.% Y sub 2 O sub 3 ) are studied using TEM, AES and XPS. No evidence of grain boundary amorphous phase was obtained. However, both EDS and XPS suggest that yttrium segregates to grain boundaries in Y-TZP. Tensile specimens of superplastic yttria-stabilized tetragonal zirconia polycrystals, Y-TZP, were microstructurally characterized by SEM and TEM. Grain boundary structure was investigated using TEM, whereas the chemical composition of grain boundaries was investigated by TEM, AES, and XPS. Specimens were examined using either a JEOL 2000FX microscope operated at 200 keV or a Philips EM400 microscope operated at 120 keV. Fracture surfaces of superplastically-deformed specimens were characterized by SEM. Newly fractured specimens were examined by XPS to gain additional information on grain boundary chemistry. Graphs, Photomicrographs. 18 ref.--A.R.