ISO 13067:2020

INTERNATIONAL ISO
STANDARD 13067
Second edition
2020-07
Microbeam analysis — Electron
backscatter diffraction —
Measurement of average grain size
Analyse par microfaisceaux — Diffraction d'électrons rétrodiffusés —
Mesurage de la taille moyenne des grains
Reference number
©
ISO 2020
© ISO 2020
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ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Terminology associated with EBSD measurement of grain size . 2
3.2 Terminology associated with grains and grain boundaries determined via EBSD . 4
3.3 Terminology associated within grain size measurement . 5
3.4 Terminology associated with data correction and uncertainty of EBSD maps . 6
4 Equipment for grain sizing by EBSD . 7
4.1 Hardware requirements . . 7
4.2 Software requirements . 7
5 Acquiring the map for grain sizing by EBSD . 7
5.1 Specimen preparation . 7
5.2 Defining specimen axes . 7
5.3 Stage positioning and calibration . 8
5.4 Linear calibration . 8
5.5 Preliminary examination . . 8
5.6 Choice of step size . 8
[7][8]
5.7 Determination of the level of angular accuracy needed .10
5.8 Choice of areas to be mapped and map size .10
5.9 Considerations when examining plastically deformed materials .11
6 Analytical procedure .11
6.1 Definition of boundaries .11
6.1.1 Grain boundary angles .11
6.1.2 Handling incomplete boundaries .12
6.1.3 Dealing with special boundaries .12
6.2 Post-acquisition treatment of raw data .12
6.3 Data-cleaning steps .12
6.4 Measurement of sectional grain size .16
6.5 Calculation of average grain size .16
6.6 Representation of data .17
7 Measurement uncertainty .17
8 Reporting of analysis results .18
Annex A (informative) Grain size measurement .20
Annex B (informative) Reproducibility.22
Bibliography .25
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
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described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 202, Microbeam analysis.
This second edition cancels and replaces the first edition (ISO 13067:2011), which has been technically
revised. The main changes compared to the previous edition are as follows:
— Data from a round robin (Annex B) have been used to:
— Include information on expected precision (Clause 7 and Annex B);
— Include more detail on sources of errors (Clause 7);
— Clarify statements on minimum numbers of grains measured (5.8) and acceptable clean up
procedures (6.3–6.3);
— Clarify the distinction between sectional grain size measured on a 2D section and average
grain size determined from some 2D measurements of grain sections which can be related by
stereology to the 3D grain size;
— Additionally, improvements have been made to the description of calculation of average values
(6.5) and representation of the data (6.6).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved

Introduction
The mechanical and electromagnetic properties of engineering materials are strongly influenced
by their crystal grain size and distribution. For example, strength, toughness and hardness are
all important engineering properties that are strongly influenced by these parameters. Both bulk
materials and thin films, even as narrow two-dimensional structures, are influenced by grain size. For
this reason, it is important to have standard methods for its measurement with commonly used and
agreed terminology. This document describes procedures for measuring average grain size from maps
of local orientation measurements using electron backscatter diffraction.
INTERNATIONAL STANDARD ISO 13067:2020(E)
Microbeam analysis — Electron backscatter diffraction —
Measurement of average grain size
1 Scope
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
[1]
specimen . 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.
NOTE 1 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.
NOTE 2 The method also lends itself to the measurement of the grain size of complex materials, for example
those with a significant duplex content.
NOTE 3 The reader is warned to interpret the results with care when attempting to investigate specimens
with high levels of deformation.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 16700, Microbeam analysis — Scanning electron microscopy — Guidelines for calibrating image
magnification
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
ISO 23833, Microbeam analysis — Electron probe microanalysis (EPMA) — Vocabulary
ISO 24173, Microbeam analysis — Guidelines for orientation measurement using electron backscatter
diffraction
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 24173 and ISO 23833 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1 Terminology associated with EBSD measurement of grain size
3.1.1
step size
distance between adjacent points from which individual EBSD patterns are acquired during collection
of data for an EBSD map
3.1.2
pixel
picture element
smallest area of an EBSD map, with the dimensions of the step size (3.1.1), to which is assigned the
result of a single orientation (3.1.3) measurement made by stopping the beam at a point at the centre of
that area
3.1.3
orientation
mathematical description of the angular relationship between the crystal axes
...