EBSD = Electron Backscatter Diffraction
EBSD is a technique that allows:
• Crystallographic Orientations
• Misorientations
• Texture trends
• Grain size and boundary types
• Phases
To be characterised and quantified on a sub-micron scale
© Oxford Instruments Analytical Limited 2001

• 1928 Kikuchi lines observed in TEM
• 1954 Alam: patterns obtained in TEM
• 1973 Venebles: patterns recorded on film in SEM
• 1980 Patterns imaged with low light TV cameras
• 1990 Automatic pattern solving using Hough transform
• Present day
– Local orientation and misorientation measurements
– Crystal Orientation Mapping (COM)
– Special grain boundaries imaged
– Special textures revealed
– Grain sizing
© Oxford Instruments Analytical Limited 2001

Introduction to EBSD - Hardware
• Schematic layout of components
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Introduction to EBSD - Collection
Geometry
• 70.5 deg tilt
• Approx. 70 steradian of pattern detected
• Distances shown are arbitrary
© Oxford Instruments Analytical Limited 2001

Introduction to EBSD - Forward
Scattered Electron Imaging (FSE)
• FSE greatly enhances diffraction contrast in imaging
• Grains and grain boundaries are clearly revealed
© Oxford Instruments Analytical Limited 2001

Introduction to EBSD - FSE Examples
• Nickel
• Austenitic
Stainless
Steel
© Oxford Instruments Analytical Limited 2001

Introduction to EBSD - Crystal
Orientation Mapping (COM)
• Crystal uses reference electron image
• Orientation obtained at every pixel
• Color derived from inverse Pole Figure color key
• Hough transform for every pixel stored for post acquistion reprocessing
© Oxford Instruments Analytical Limited 2001

Introduction to EBSD - Color Key for
COMs
• COM with
Inverse Pole
Figure color key for cubic material
• Red = 100
• Green = 110
• Blue = 111 planes parallel to the surface
© Oxford Instruments Analytical Limited 2001