Five dimensional grain boundary distribution for yttria stabilized zirconia based on experimentally determined macroscopic boundary parameters

Distributions showing the frequencies of occurrence of grain boundaries as functions of their 5 macro-scopic boundary parameters have been computed for a set of yttria-stabilized zirconia samples sintered at different conditions and thus having different grain sizes. For this purpose, datasets containing both grain misorientation and boundary plane parameters have been collected by the means of the 3D EBSD technique. Then, the 5-parameter distributions have been computed using the approach based on kernel density estimation. A few top peaks are visible in all of the obtained distributions. Their heights exceed the level of the random distribution by at least about 3 multiples of the corresponding statistical errors. The list of favored grain boundaries includes the sigma 3 / ( 111 ) and sigma 11 / ( 1 ((1) over bar) 3 ) boundaries, as well as the boundaries having both the boundary plane (100) and misorientation by 10 to 37 about the [100] axis. The largest of the collected dataset containing 64,506 distinct grain boundaries, and being probably the largest dataset of this kind ever collected for zirconia, allowed to study e.g. rare boundaries like those with high sigma misorientations about the [110] axis. (C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study computed the probability distributions of grain boundaries based on their macroscopic boundary parameters for yttria-stabilized zirconia samples with different grain sizes. The datasets collected using 3D EBSD technique provided both grain misorientation and boundary plane parameters. The distributions of the five parameters were computed using kernel density estimation and showed several prominent peaks that exceeded the level of random distribution. The collected dataset, containing 64,506 distinct grain boundaries, is the largest of its kind for zirconia and allowed for the investigation of rare boundaries.