Grain Boundary Characterization in Yttria-Stabilized Zirconia by TEM Spectrum Lines

Abstract

The superplasticity exhibited by some fine-grained ceramics, notably 3-mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP), offers interesting possibilities to lower manufacturing costs by near net shape forming. Both glassy and crystalline materials have been added to pure 3 Y-TZP to limit grain growth and promote grain boundary sliding during sintering and isostatic pressing. EDS spectrum lines have been used to characterize the distribution and extent of additive phases, but were not able to map some light-element components of additives (e.g., O and B in borosilicate glass). Additionally, quantification of the Si Kα peak was compromised by overlap with the Y L and Z L peaks. To both improve light element sensitivity and investigate potential changes in oxygen bonding at the grain boundaries, undoped 3 Y-TZP and 3 Y-TZP powders processed with 1 wt% barium silicate have been examined with TEM spectrum lines. Additionally, some elemental mapping has been performed. TEM specimens were examined in a 300 kV LaB6Philips CM30T equipped with a Gatan imaging filter (GIF) at the ORNL SHaRE User Facility.