BS ISO 13067:2020

This document describes procedures for measuring average grain size derived from a two-dimensional polished cross-section using electron backscatter diffraction (EBSD).

This document describes procedures for measuring average grain size derived from a two-dimensional polished cross-section using electron backscatter diffraction (EBSD). This requires the measurement of orientation, misorientation and pattern quality factor as a function of position in the crystalline specimen[ 1]. The measurements in this document are made on two dimensional sections. The reader should note carefully the definitions used (3.3) which draw a distinction between the measured sectional grain sizes, and the mean grain size which can be derived from them that relates to the three dimensional grain size. NOTE1 While conventional methods for grain size determination using optical microscopy are well-established, EBSD methods offer a number of advantages over these techniques, including increased spatial resolution and quantitative description of the orientation of the grains. NOTE2 The method also lends itself to the measurement of the grain size of complex materials, for example those with a significant duplex content. NOTE3 The reader is warned to interpret the results with care when attempting to investigate specimens with high levels of deformation.