| Project Overview

Electron Backscatter Diffraction (EBSD) is a microanalytical technique based on Scanning Electron Microscopy (SEM). By analyzing the diffraction patterns (Kikuchi patterns) generated from backscattered electrons produced through the interaction of an incident electron beam with the sample, crystallographic information of the sample can be obtained. Its core principle is Bragg’s diffraction law (2dsinθ = nλ), in which the electron beam wavelength (λ), interplanar spacing (d), and Bragg angle (θ) collectively determine the diffraction condition. The diffraction pattern is determined by the crystal plane system of the crystal. Different crystal structures produce unique Kikuchi patterns. By comparing these patterns with crystallographic databases, functions such as phase identification and distribution, grain size analysis, grain boundary classification, and crystal orientation analysis can be achieved.

| Test Objective

Crystal Orientation Analysis

By matching Kikuchi patterns with standard crystallographic data, crystal orientation angles (such as Euler angles or Miller indices) can be calculated. Orientation Imaging Maps (OIMs) are then generated to visually display the orientation distribution of grains.

Grain Boundary Types

Low-Angle Grain Boundaries (LAGB): Misorientation < 15°, typically representing subgrain boundaries.

High-Angle Grain Boundaries (HAGB): Misorientation > 15°, generally representing true grain boundaries.

Special Grain Boundaries: For example, twin boundaries (Σ3 boundaries) can be identified by calculating the Coincidence Site Lattice (CSL).

Phase Analysis

Phase attribution of each pixel can be determined through pattern matching, enabling the generation of phase distribution maps that visually display phase distribution.

Grain Size Measurement

Based on grain boundary detection results, grain size is calculated using the area method or the intercept method. A grain size distribution histogram is generated, and the average grain size along with the standard deviation is reported.

Texture Analysis

Statistical distribution of grain orientations is characterized through Pole Figures or Orientation Distribution Functions (ODF), thereby revealing the effects of material processing on microstructural evolution.

Strain Analysis

By evaluating variations in crystal orientation and pattern quality, the distribution of strain or residual stress within the sample can be assessed. Strain can be quantitatively analyzed through features such as grain boundary curvature and orientation gradients. Combined with Full Width at Half Maximum (FWHM) analysis or deformation mode studies, stress accumulation can be further investigated.

| Test Standard

GB/T 36165 Determination of average grain size of metal. Electron backscatter diffraction (EBSD) method

ISO 23703 Microbeam analysis — Guidelines for misorientation analysis to assess mechanical damage of austenitic stainless steel

YB/T 4677 Method of texture of steel - Electron backscatter diffraction (EBSD)

ASTM E2627-13 Standard Practice for Determining Average Grain Size Using Electron Backscatter Diffraction (EBSD) in Fully Recrystallized Polycrystalline Materials

| Service Products / Fields

Electronic products, metallic materials, ceramic materials, semiconductor materials, mineral materials, and others.

| General Sample Requirements

Maximum sample dimensions are 20 mm × 20 mm × 5 mm (height). The top and bottom surfaces shall be parallel, and the sample shall be polished and subjected to stress-relief treatment (such as vibratory polishing or cross-sectional preparation, CP).

| Project Advantages

1. Professional Team: Equipped with a number of highly experienced testing engineers and technical experts.

2. Advanced Equipment: Equipped with internationally leading testing instruments to ensure accuracy and reliability of results.

3. Efficient Service: Rapidly responding to customer needs by providing a complete set of hazardous substance testing services for PCBs.

4. Authoritative Certification: The laboratory is certified by ISO/IEC 17025, ensuring that test reports have international credibility.