Simulation-based super-resolution EBSD for measurements of relative deformation gradient tensors

Area of Science:

• Materials Science
• Crystallography
• Computational Materials Science

Background:

• Electron Backscatter Diffraction (EBSD) is crucial for microstructural analysis.
• Accurate strain and orientation mapping requires high-resolution EBSD patterns.
• Low-resolution patterns often limit the precision of deformation gradient tensor measurements.

Purpose of the Study:

• To develop a data analysis approach for precise EBSD measurements from low-resolution Kikuchi patterns.
• To improve the accuracy of isochoric relative deformation gradient tensor calculations.
• To demonstrate the application of the method for analyzing deformation in silicon wafers.

Main Methods:

• Utilizing high-resolution Kikuchi pattern simulations for supersampling.
• Applying best-fit determinations to extract tensor parameters from experimental patterns.
• Employing finite element simulations for interpreting strain and rotation measurements.

Main Results:

• Achieved significant precision improvement in tensor parameters from low-resolution EBSD data.
• Demonstrated high-resolution orientation and strain analysis on silicon wafers with varying pattern resolutions.
• Observed noise levels around 1x10^-4 in relative deviatoric strain norm and rotation angles.

Conclusions:

• The simulation-based supersampling approach enhances EBSD analysis precision.
• The method allows for a significant reduction in required pattern data size (up to two orders of magnitude).
• EBSD pattern resolutions of 256x256 pixels may suffice for many pattern matching tasks.