Variability in EBSD statistics for textured zirconium

Abstract

Zirconium is an important structural material, and, as with other hexagonal close-packed (HCP) metals, the mechanical properties depend on both slip and twinning. Electron backscatter diffraction (EBSD) from two-dimensional (2D) metallographic sections has previously been used to identify and quantify deformation twinning to support development of physically based plasticity models for HCP metals. However, the stereological assumptions used to generate twin statistics from a single 2D section have not been fully validated against potential sources of measurement artifacts or biases potentially arising from the strong initial material textures and crystallographic nature of twinning. This work addresses these concerns by comparing results from three orthogonal directions in a deformed sample. Few differences are observed in the twin statistics based on viewing direction. Statistical variability of microstructures is a bigger factor in the comparison of twin statistics than viewing direction. {101¯2} twinning does not occur homogeneously throughout the microstructure during a compression test. However, useful twin statistics can be successfully extracted from a single metallographic section.