Ni-base superalloy single crystal (SX) mosaicity characterized by the Rotation Vector Base Line Electron Back Scatter...

Area of Science:

• Materials Science
• Crystallography
• Electron Microscopy

Background:

• Studying crystal mosaicity in single crystals is crucial for understanding material properties.
• Existing methods for orientation imaging have limitations in quantifying subtle crystallographic deviations.

Purpose of the Study:

• To introduce and validate the novel Rotation Vector Base Line Electron Back Scatter Diffraction (RVB-EBSD) method.
• To enable the quantification of crystal mosaicity and associated geometrically necessary dislocations (GNDs) in Ni-base superalloy single crystals.

Main Methods:

• Development of the RVB-EBSD technique, building upon cross-correlation EBSD procedures.
• Application of Gaussian band pass filtering to enhance over 500,000 experimental patterns.
• Implementation of a rotation vector approximation and a baseline correction function.

Main Results:

• The RVB-EBSD method successfully quantifies small crystallographic deviation angles between dendrites.
• The technique allows for the interpretation of accommodation processes in terms of geometrically necessary dislocations (GNDs).
• A novel intuitive color-coding system enhances the visualization of crystal mosaicity features.

Conclusions:

• The RVB-EBSD method provides a powerful new tool for correlative orientation imaging in scanning electron microscopy.
• This technique offers significant potential for detailed analysis of crystal mosaicity and defect structures in advanced materials.