Characterization of the Grain‐Boundary Character and Energy Distributions of Yttria Using Automated Serial Sectioning and EBSD in the FIB

A dual‐beam focused ion beam scanning electron microscope was used to collect a series of parallel electron backscatter diffraction maps of polycrystalline yttria. Using characteristics of the triple junctions, the individual layers were aligned and the geometries of the grain‐boundary planes between the layers were determined. This information was used to calculate the five‐parameter grain‐boundary character distribution (GBCD) and grain‐boundary energy distribution (GBED). The GBCD derived from the three‐dimensional data was qualitatively the same as that derived from a stereological analysis of the same data. The anisotropy in the GBCD of yttria is relatively weak compared with other ceramics and is inversely correlated to the GBED.