Electron Backscatter Diffraction (EBSD)

EBSD can be used to analyse the grain shape, size and orientation

Introduction

Crystalline and polycrystalline materials can be analysed using Electron Backscatter Diffraction (EBSD) to study the crystallographic structure, such as: grain orientation, misorientation, texture measurement, grain size distribution, grain boundary type and phases. This technique can also be used simultaneously with EDS .
Typically, the sample is tilted to 70° to maximise the intensity of diffracted signal.
The electrons are subsequently diffracted by the tilted sample and the pattern is detected with a fluorescent screen.
The pattern is characteristic of the crystal structure and orientation and is named kikuchi pattern.

Electron microscopy image in bright colours

Understanding crystallography

EBSD is useful for a range of samples, including in metallurgy and materials analysis as well as geological analyses. Not only can EBSD data provide inside into the stress and strain of a sample, it is also possible to analyse the effect of techniques such as annealing on materials or be used as a tool to solve a reason for faults in a product.

In rocks, EBSD data can inform us whether a rock has been recrystallised, analyse palaeo-stress the sample has undergone or even determine deformation mechanisms in rocks in tectonic environments.