A new method for calculating interplanar spacing to distinguish between similar phases in EBSD

Area of Science:

• Materials Science
• Crystallography
• Electron Microscopy

Background:

• Commercial electron backscatter diffraction (EBSD) systems struggle to differentiate phases with similar interplanar angles, like Al and Si, due to reliance on angle matching.
• Interplanar spacing is a more reliable identifier but lacks precision in standard EBSD pattern indexing.

Purpose of the Study:

• To develop an efficient and accurate method for measuring interplanar spacing using corrected reciprocal-lattice vectors (RLVs) for phase discrimination.
• To enhance the accuracy of lattice spacing calculations in EBSD, particularly for challenging patterns.

Main Methods:

• Automatic identification of Kikuchi bands using pattern rotation and grey gradient recognition.
• Accurate extraction and correction of reciprocal-lattice vectors (RLVs) to precisely determine lattice spacing.
• Phase discrimination based on interplanar spacing matching for materials like Al and Si.

Main Results:

• Reduced average error in interplanar spacing measurements by 50.611% across five Kikuchi patterns.
• Achieved an average accuracy of 1.644% for lattice spacing calculations.
• Demonstrated the ability to distinguish structures with lattice spacing differences as low as 3.3%, effective for fuzzy or incomplete patterns.

Conclusions:

• The proposed method significantly improves lattice spacing calculation accuracy in EBSD by correcting RLVs.
• This approach offers a new strategy for differentiating similar crystalline phases and is compatible with existing EBSD systems.
• The method enhances EBSD's capability to analyze materials with similar crystallographic properties, even with low-quality patterns.