ISO 24173:2024

Overview

ISO 24173:2024 - Microbeam analysis: Guidelines for orientation measurement using electron backscatter diffraction (EBSD) provides practical guidance to generate reliable and reproducible crystallographic orientation measurements using EBSD. The standard covers requirements for specimen preparation, instrument configuration, instrument calibration, data acquisition, uncertainty estimation and reporting. It replaces the 2009 edition and includes informative annexes on the principle of EBSD, specimen preparation, and a brief introduction to crystallography and EBSP indexing.

Key Topics and Requirements

• Scope and normative references: Addresses laboratory competence and measurement uncertainty with references to ISO/IEC 17025 and ISO/IEC Guide 98-3 (GUM).
• Equipment for EBSD: Guidance on EBSD detectors (scintillators plus CCD/CMOS cameras), SEM/FEG-SEM, combined SEM-FIB and EPMA configurations, and recommended operating stability checks.
• Specimen preparation and alignment: Emphasizes surface quality and tilt (commonly ≈70°) because EBSD is a surface-sensitive technique (signal depth of tens of nanometres). Annex B provides specimen preparation guidance.
• Data acquisition parameters: Practical recommendations for microscope operating conditions, detector and working distances, camera integration/exposure time, pixel binning, EBSP averaging and background correction, and band detection using methods such as the Hough transform.
• Calibrations for indexing: Procedures needed to calibrate the pattern centre, detector geometry and other parameters required for reliable EBSP indexing.
• Analytical procedure and stability checks: Defined steps for pre-test setup, equipment stability verification and EBSD mapping workflows.
• Measurement uncertainty and reporting: Guidance on estimating uncertainty of absolute and relative crystal orientation measurements (orientation accuracy can be on the order of ≈0.5° in well-controlled tests) and standardized reporting practices.

Applications and Who Uses It

ISO 24173:2024 is intended for:

• Materials scientists and metallurgists performing crystallographic orientation mapping and texture analysis.
• Electron microscopists and EBSD system operators in research, failure analysis and quality control.
• Laboratories seeking reproducible EBSD data for grain size, texture, boundary characterization, phase identification and 3D microstructural studies (e.g., combined EBSD with FIB serial sectioning).
• Accreditation and calibration labs referencing ISO/IEC 17025 for competence.

Practical applications include quantitative microstructure analysis, texture determination, grain-boundary characterization (including twins), and high-resolution orientation mapping using TKD/t-EBSD for nanoscale samples.

Related Standards

• ISO/IEC 17025 - General requirements for the competence of testing and calibration laboratories
• ISO/IEC Guide 98-3 (GUM) - Uncertainty of measurement

Keywords: ISO 24173:2024, EBSD, electron backscatter diffraction, EBSP, crystallographic orientation, specimen preparation, instrument calibration, pattern centre, Hough transform, measurement uncertainty.