Quaternion-based disorientation coloring of orientation maps

Area of Science:

• Materials Science
• Crystallography
• Data Visualization

Background:

• Crystallographic orientation data, often visualized using Electron Backscatter Diffraction (EBSD) maps, requires effective color coding for interpretation.
• Existing color coding techniques can suffer from ambiguities, particularly when representing complex disorientation parameters.

Purpose of the Study:

• To develop a new color coding technique for crystallographic orientation data using quaternions.
• To create a color space where perceived color differences correlate with mutual disorientation angles between crystal orientations.
• To overcome color ambiguities present in current visualization methods.

Main Methods:

• Utilized quaternions to represent crystallographic orientation data, including axis and angle pairs.
• Developed a color space where Euclidean distances in quaternion vector space correspond to disorientation angles.
• Applied the technique to EBSD maps for visualization.

Main Results:

• The proposed quaternion-based color coding ensures perceived color differences are proportional to disorientation angles.
• Successfully avoided color ambiguities common in other crystallographic data visualization methods.
• Enabled unambiguous visualization of sub-grain orientation differences within grains.

Conclusions:

• Quaternion-based color coding offers a superior method for displaying crystallographic orientation data.
• This technique enhances the accuracy and clarity of EBSD map interpretation.
• It provides a robust solution for visualizing complex microstructural features and grain boundaries.